1/3: The Ruy - the Sicilian is generally just very Sicilianny, and much of the fireworks in the Sicilian can be 'learnt' elsewhere... whereas the Ruy will help you in all positions.
Ruy Lopez, Sicilian

1) SICILIAN is my fav.. but i will go for RUY..
2) it will depend on the player's method of understanding the moves, memorizing wont do ( oops..!! I NEVER memorize, & neither i can..)
3) RUY surely has greater effect on positions than SICILIAN.

I play 1...e5 in response to 1.e4 so I've played the ruy lopez alot. It's really the only opening after 1. e4 e5, where white can take control of the center by force, without giving to much in return. As white I play 1.e4 so I've played the sicilian alot, but I played the morra smith gambit until recently I started playing the open sicilian. So I don't completely understand all the ins and outs of the sicilian, but the c5 pawn break is such a common theme in so many defenses, I can see how understanding the sicilian would really improve your playing.
My thoughts:
1. I would make a random choices. Both openings are huge, with tens of different lines/transposition possibilities.
2. Spanish is kind of easy to learn if you are sure your opponent will not go for a Marshall attack. OTB one must be well-prepared against it. I've always played 1. e4, and if 1...c5, I went for Alapin, 2. c3. I find this opening easy to learn and playable. The drawback is that it poses Black no problems and it tends to be drawish. For me, Alapin was the only choice and the opening which allowed me to keep playing 1. e4. Sicilian is way too big to master. Way too many sharp lines in which it does matter whether you know the theory or not.
In your case, if you never played Sicilian or Ruy and did very well without them, I don't see why to bother to learn them?

I'm certainly not a strong player by any measure, but my personal preference is definitely not for e4/e5 games. I played e4 when learning chess, and just didn't really like it very much in general, and e4/e5 least of all. Very limited study time also contributes to my preference for d4 as white and away from e5 and c5 as responses to e4 as black.
However, if said oracle did grant my wish, I would without hesitation choose the Sicilian. e4/e5 games simply don't appeal to me. Perhaps this is due to a lack of understanding or ambition, but I've never really enjoyed those positions as much as others.
I don't have any worthwhile input into the other two questions, so I'll keep my mouth shut.

1. Scotch Game. The positional motifs on the White side are somewhat similar to a classical Sicilian, but only by a stretch.
2. I'm assuming that a master already has a strong understanding of openings in comparison to the general audience.
3. The Ruy Lopez is only a "positional masterpiece" if both sides allow it to be so. Indeed, the main line(s) in the Closed Ruy hold(s) off all captures for 20-30 moves, but either side can create a perfectly sound deviation which simplifies the position. This applies more to White than Black, since Black's early options are limited, e.g. the Open Ruy.
By the way, what makes 1. e4 c6 a "Half Sicilian"? That's like calling 1. d4 f6 a "Half Dutch".

BlackWaive, Dmytro:
Masters should compare their understanding of openings with their peers, not with the general audience. Also, masters do not know already the ideas in all openings.
I would not enjoy playing the white (or black) side of an open Sicilian against a 2200-2300 rated player who has earned their way up to that rating by playing open Sicilians from both sides. I would take up way too much time trying to develop a middlegame plan when my opponent would already know all the basic potential plans and would be choosing amongst them.
For example: For any opening, and especially for these two, you should know when it's appropriate to begin a pawn storm. You should know some typical piece placement setups. You should know some typical attacking setups and some defensive motifs. You should know the relative values of the bishops. Is white looking to keep his light squared bishop and trade his dark squared bishop? Is he looking to trade a pair of rooks? Maybe he wants to keep as many minor pieces in the game as possible to help the attack.
You can't come up with the answers over the board, and especially for the long-range plans once you figure out what your opponent is doing it will be too late.

1. I have played both, the ruy for about 3-4 years of OTB when I first started, 1972 to about 1976. I stopped playing it because I felt I could be more successful playing the Nimzovich (1 e4 Nc6) against lower rated players. I played the Ruy until I was in the 1800 range USCF. I didn't start playing the Sicilian until the early 1990's after I was already rated over 2200. I now have beening playing the Sicilian Dragon about 19 years. I opt for knowledge of the Sicilian.
2. I feel that after playing the Sicilian for 19 or so years, I felt comfortable playing it against everyone, lower, equal to or higher rated after about 5 years of rather casual study. I even enjoy the games I lose, there are certainly more exciting (and more painful) loses than when I lost Ruy games.
3. I am not sure what you mean by "leveraged". I need a better understanding of what you are asking.
mnag

1. The Sicilian, no contest. It's a long way from 1 e4 to the Ruy Lopez, and neither White nor Black can guarantee that a Ruy will ensue. White has to be prepared for the French, Caro, Pirc, and, of course, the Sicilian. A Black player looking for a Ruy Lopez might find himself instead in a King's Gambit or (even) a Traxler
If you are a Black player looking for a Sicilian all you need is 1 e4 and you're in business. Granted, you may not get the line you want, but if you answer 1 e4 with 1...c5 your chances of getting to use your Sicilian expertise are pretty good.
2. No idea. We patzers are of course totally mystified by the thinking process of Masters.
3. I think this notion arises out of the seemingly random tactical melees that often arise from open Sicilians, but I'm not sure that precludes using the opening to learn a lot of positional ideas. I've used it (the Kan in particular) to painfully learn the pitfalls of cramped positions. There is the 'reversed English opening' idea that may give rise to some cross-pollination. You certainly learn a ton about playing on the wings in nearly any Sicilian.

I'm not quite an expert, but I play 1.e4, 1...e5, and 1...c5 all, so I find this a very interesting question.
1. Based on my current knowledge, I would choose Sicilian, but that's based on my immodest belief that I understand the Ruy better than your average player of my level. If I lost that knowledge, I would definitely choose Ruy, because I feel that the understanding I have gained about how to build an attack in the Ruy serves me well as White in the Open Sicilian as well.
2. I'm not a master, so it's hard for me to speculate on what opening preparation really means at that level. That said, I would think that it is easier to learn the ideas in the Ruy Lopez, because other than the bizarre outliers (Bird's, Schliemann, etc.), the ideas are fairly consistent among the variations. In fact, I think you can get a very strong foundation from Danny King's excellent book, Mastering the Spanish.
Sicilian variations, by contrast, are quite diverse. I find it hard to see how someone would consider themselves an expert on the whole Sicilian -- it's like saying you're an "e5 expert". Most everyone specializes in certain variations (Najdorf, Sveshnikov, Dragon, e6 formations, etc.). The ideas in some of those variations are consistent & clear; not so much in others. Kasparov has said as much about the Najdorf -- what works in one position doesn't in another, and there's no good rule to follow; you just have to know.
3. I think I would say yes, but I'm not 100% sure about it, because I have applied learnings from the Sicilian elsewhere as well. One thing you see a lot in the Ruy, which is hard to find so clearly in other openings, is a vivid illustration of how a space advantage allows you to probe weaknesses on alternate fronts, and switching back and forth makes a defender's task difficult or impossible. So many other openings you focus on one point or area of attack, and don't let up until you've achieved something concrete, and only then go elsewhere. A good Ruy can illustrate attacking everywhere at once; it's kind of unique like that.
Hopefully that's helpful. At the least, it was interesting to ponder.

I think Ruy Lopez is an excellent primer in chess strategy, but Sicilian teaches you to fight, which is useful as well...
As for the time necessary to learn decently Ruy or Sicilian at the 2200 level, it's difficult to say, but probably you need less time for Ruy (except if you enter the Marshall), as your margin of error is greater : in many cases you only risk to land into an equal but nevertheless playable position.
I'd say 40hrs of serious work with good instructional material available for the Ruy Lopez and probably 3 times more for a mainstream sicilian and the various Anti-Sicilians.
If I could choose, I'd be quite happy to master the Najdorf tomorrow morning

I like the Ruy Lopez only if I'm white. I hate versing it so I choose Sicilian as I'm very good at that opening!

Sicilian because if I'm white, I have no control over black's next move. If he plays a sicilian and I don't know how to play the Yugoslavian attack against the dragon, I'll lose for sure. But if someone plays the ruy lopez, it's far easier to play for a draw because swapping pieces is far more available

If you want to know which one will help your chess in general, my opinion is without a doubt the ruy lopez. This may well go against most others' opinions, but I think many prefer the sicilian, but that doesn't mean it benefits more to study it. It's just an opening that gives black good counterchances and often a sharp game. The ruy lopez on the other hand has subtle problems to solve with the center (when should white close it, stuff like that) and some of the deepest closed positions with maneouvers and the possiblity for either player to play on both kingside or queenside (though of course white has more potential play in the closed ruy). I mean if you master those positions, you have to be able to be good enough to excell in many other, probably more simple closed positions that might happen even if you're not planning to actually play the ruy but just study it. I'm sure like any opening, the sicilian teaches you stuff, but not really more than the average opening, it's just that the siclian is an attractive choice for a lot of people. But I think the ruy lopez (and also the queen's gambit) is just one of those openings that can really build your understanding of the game.
The open ruy is pretty instructive too, I believe white is supposed to control d4, but I don't have much experience with the open.
I've read somewhere that you don't really know much about chess unless you know the Ruy Lopez. It's a whole-board opening from both sides. Both white and black must pay attention to what the other is doing on both flanks. What I read into the statement is that learning all about the Ruy Lopez will have a leveraged effect on the rest of your chess game, no matter the opening. Sounds pretty powerful...
The Sicilian. The most popular response to 1.e4 -- and 1.e4 is (I think) the most popular opening move for white. Becoming an expert in the Sicilian -- whatever that means -- is clearly some sort of a holy grail for chess players. If (and yes I realize it's a big if) you could become an expert in the Sicilian, you would have such a leg up on your competition that it might be difficult for them to overcome.
Several questions I've got here -- please chime in with your thoughts on any of my questions, or just with your own thoughts on either of these two fantastic openings.
And a bit of information about me: I don't play either of these openings. I am a 1.d4 player, and against 1.e4 I play the "Half Sicilian": 1.e4 c6. :-)