What opening do you think is the begginers worst enemy?

I am convinced that the reason the Sicilian is so dangerous for beginners,(and sometimes intermediate players who are unversed in its theory) is that in many lines every single tempo is crucial and playing even a slightly inaccurate move can see your position collapse.

The French is a bit less difficult to play I think for a beginner although I used to get destroyed by 4. Bg5 in the French when I tried playing it a few times. I agreed with the comment about playing the French Exchange Variation for a beginner. 

Agree. :D

Beginners problem are the not well known lines in the opening. So try to sidestep the main lines to confuse them a little bit. 

Beginner's enemy is when they know a bit of theory and think that everybody who does things a bit differently doesn't know how to play chess. Your list is a good example, because the variations you listed are perfectly playable.

1) that's the Rubinstein French, it is played even at GM level.

2) in that Scandinavian, after white blocks the check with Be2 black plays c6 and retreats the queen to c7. In the end black's queen is well placed and white's lsB is not active. Nothing wrong with 3...Qe5+

3) playing 2.Bc4 is a bit premature, but the system with Nf3 and Bc4 deserves respect. Of course white should follow up correctly and play for c3 and d4.

4) queen pawn game with 2.e3 is a Colle/Zuckertort, even if with an odd move order. Again, legit opening.

5) this one I agree.

Beginners who play black have a hard time against the c3 Italian/Evans or the 2 knights/Prussian game. With that I don't mean just the Ng5 line but also the d4 lines.

Usually they lose the centre with black or Nf6 gets pushed around by e5. 

The King's Gambit. Even better would be the Vienna Gambit (1.e4 e5 2.Nc3 followed by f4, often after a horrible, but natural looking blunder by black) Even decent players underestimate it because it looks dubious. Actually, it is dubious, but not as dubious as it looks.

I'd have to say the Reti, English, or any other strategically rich opening since beginners usually focus mostly on tactics and don't know what to do in quiet positions. 

Russian Variation of Grunfeld. lol

Rushing Variation of Grunfeld.

Ghhh. I hate the French too. The Advance with Qb6 is my enemy, maybe I should try the exchange lines.

When I play black proper play with any system pushing the f pawn, or the QG..  I play the Pirc as black alot and when around move 5-7 white moves f4 it bothers me if I can not exploit it..

Vikings!

When a beginner tries the kings gambit and u (past 1600) does the falkbeer counter gambit.... +1

Agree with others... PIc, KID, Alekhine's, many Sicilians, obscure gambits, things like that.

French doesn't seem bad at all.  If you're clueless about the attacks your peers are likely clueless also.  The problem with the pirc for example is you think you're ok, but get a bad position and lose without either player knowing why exactly.

Well, I played this as black - I should really stick to my sicilian next time. :)

funny you would say, I have a game right now playing the pirc where it started out ok,, gained the e pawn and after a rather organic series of exchanges my position is terrible.  For the most part though up to my current rating the pirc has served me well and is responsible for many of wins against higher ranked players..  Play for a draw, developing tit for tat and every once in a while white's position collapses..

I took the OP as openings playing against, not playing.  I used to play alehkine's and plan on revisiting it soon it would be ashame to abandon all those games..  The problem with alekhine's is time, ply wise its a beast...  

Sicllian Dragon and Nadjorf because beginners memorise lines rather than understanding chess.

Sorry I took "enemy" as being an enemy of a beginner's efforts to improve. The OP seemed to be more about winning.

Enemy of a beginner's efforts to improve: Sicilian Dragon.  It is probably the sharpest variation.  One wrong move and the beginner would lose.  Sad thing is, the beginner might not even understand why he lost if he does not know the theoretical and positional aspects of the various positions.

use scotch because it's awesome and super aggressive