Giuco Piano on move 5!

I've gone in search of the correct move after the following sequence but here it says one thing and another database it says something else.  For players who actually know the main Italian lines...could you offer some advice and insight on the following options:

I see the options of

5. d3

5. d4

5. 0-0

Could you explain the differences and why you prefer one over the other?  Thanks.

5. d4 is probably the first move to consider: white tries to blow black away in the centre. After this game most often continues 5... exd4 6. cxd4 (6. e5 d5!) Bb4+! and now either simply 7. Bd2 Bxd2+ 8. Nbxd2 d5! when black manages to break  white's centre and obtains near equality or the more agressive 7. Nc3!? Nxe4 8. 0-0 with complications but according to modern theory black should be fine.

With 5. 0-0 white threatens to play 6. d4 without allowing blacks tempogaining chek Bb4+ and black is probably best adviced to take the pawn 5... Nxe4!. After 6. d4 thigs look dangerous but black should be ok after the very important resource 6... d5!.

Since black found antidote to these agressive tries white players began to employ more often the quiet positional move 5. d3 (or other openings altogether like Ruy Lopez!). 5. d3 may not promise any great opening advantage but it gives a playable position and among modern GM's it must be the most common move here. However, for the black player the other moves are more important to study as the prize for blacks mistake is much higher there. It's probably especially important to study the complications arising after 7. Nc3 Nxe4.

I only play 5. d4.

The reason is this: I played c3 to prepare a central advance, and honestly I don't see much of a point in delaying it with d3 or putting it off with 0-0. They are both fine options, just not my favorites.

I like to play 7. Nc3.

Okay...I only play this from White.  So I would like to know what is good for White.  Thank you for the excellent and informative response Shakaali.  And ty Paul for giving more support to it. 

I do have a couple questions...

You seem to suggest Black will have complications...but it seems to me that White is having a bit of complication too? 

Drizz...White must lose the pawn?  And what is the compensation specifically so I know how to use it...

7. Bd2 won't lose a pawn, but 7. Nf3 will. But at the end of the position that I called mainline, he is down. White would hope to compensate by making an attack on his opponent's king using the open e-file and taking advantage of the fact that black has not castled. It's a very aggressive line. Here's an example:

whoa...that's a lot of moves in between getting that piece back.  hmm. 

It's garuanteed though. Both of the knights were threatened.

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.c3 Nf6 5.d4 exd4 6.cxd4 Bb4+ 7.Nc3 Nxe4 8.0-0 Nxc3 9.d5 Bf6 10.Re1 Ne7 11.Rxe4 d6 12.Bg5 Bxg5 13.Nxg5 and black is under extreme pressure.

13...0-0 14.Nxh7 Kxh7 is almost impossible for black to survive over the board.

13...h6 14.Qe2 hxg5 15.Re1 Be6 16.dxe6 f6 17.Re3 with lots of fun.

13...h6 14.Bb5+ Bd7 15.Qe2 Bxb5 16.Qxb5+ Qd7 17.Qxb7 0-0 18.Rae1 Ng6 19.Nf3 Rfb8 20.Qa6 Rxb2 21.Nd4 Ne5 22.h3 with many complications, but white is okay.

If you like complications, take it for a spin.

9....Bf6 is the main line but here's a more common move, at least in my experience.

You are losing me after 8...Nxc3.  Could you post the line on a board?

Oops, thanks for the catch.  8...Bxc3 is the main line.

Both players certainly face complications there so if you are not prepared to study them this line is probably not for you. However, Studying this kind of complicated stuff is bound to increase one's understanding of chess in general and might therefore be a good idea from time to time.

I don't actually really play this stuff but I've read that objectively speaking white is fighting to equalize after 7. Nc3 but that is assuming black knows the correct defence. The thing is that amateurs should not take GM theory too seriously. I would imagine that this line could actually be really efficient (assuming you study it) in amateur games since most lower rated players may not know the correct defence. When you gain strength and your opponents start to defend properly (somewhere near candidate master, I would assume) you can swich opening. Altough I don't really play this stuff I recall the following nice miniature from the time I had only played chess seriously for few years - maybe it will give you inspiration.

P.S. It seems i got my revenge over paulgottlieb. Couple days ago i was going to post some analysis to another thread but he beat me to it!

Shakaali...wow, I love that game.  I have been reading about the opening with 5. d4 and apparently this player fell into one of the main traps of the line...which is started by capturing with 8...Nxc3 and then taking the queenside rook with the bishop.  Apparently in this line you can take Black's queen. 

I'm also playing a game right now in this line and it's very exciting and fast.  I think I'm going to throw 5. d3 out the window.