Openings with 'critical' moves

I often play OTB against older people with limited opening preparation and am looking for ways to get a maximum practical advantage out of that by using (sound) sharp openings that my opponent must be familiar with, which they usually aren't.

In these cases I like to play:

• the Vienna gambit: 1.e4 e5 2.Nc3 Nf6 3.f4 where many won't play 3...d5!
• the Urusov gambit: 1.e4 e5 2.Bc4 Nf6 3.d4!? exd4 4.Nf3 Nxe4 4.Qxd4 when "White has a very strong attack" (-Alekhine) as in http://www.chessgames.com/perl/chessgame?gid=1121052, while black can transpose to the Two Knights with 4...Nc6 most of my opponents don't like to play this
• the Tal variation of the Caro-Kann Advance (1.e4 c6 2.d4 d5 3.e5 Bf5 4.h4 threatening to trap the bishop and now 4...h6 5.g4 Bh7? loses to 6.e6! so black has to retreat and become passive as in http://www.chessgames.com/perl/chessgame?gid=1311652), or the Bayonet attack with 4.Nc3 and 5.g4 gaining even more space
• the Ulvestad Two Knights: 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 b5 where most won't find 6.Bf1! (have yet to encounter someone who does :P)
• the Riga variation in the Ruy: 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.0-0 Nxe4 6.d4 cxd4?! 7.Re1 d5 when it is hard for white to find the correct moves after 8.Nxd4 Bd6! preparing Bxh2+ and even if he does, the endgame is decent for black
• the Accelerated Dragon when white players who treat it as a normal dragon get punished, or lose material when they omit Bb3
• the Budapest gambit: 1.d4 Nf6 2.c4 e5!? 3.dxe5 Ng4 when white can easily get in trouble when he tries to hold on to the pawn, or when he grabs too much space leaving interior weaknesses, or when he gets underdeveloped (black always gets piece activity)
• the Albin Countergambit: 1.d4 d5 2.c4 e5!? 3.dxe5 d4 when white will stand badly if he doesn't find the proper developing plan with g3/Bg2/Nbd2/a3 and black has nice positional compensation regardless, e.g. http://www.chessgames.com/perl/chessgame?gid=1328801 I like this even better than the Budapest now since white can't just give the pawn back with a decent position.

Does anyone have other suggestions, especially against the Sicilian?

The Alekhine-Chatard attack against the French Defense.  1. e4 e6  2. d4 d5  3. Nc3 Nf6 4. Bg5 Be7 5. e5 Nfd7 6. h4!

Great thread, thank you!

One question about the Riga - if 9. Nxc6 Bxh2+ 10. Kxh2, does black have to take the draw from perpetual check after 10...Qh4+ 11. Kg1 Qf2 12. Kh1/h2 Qh4+, or does he have reasonable chances in playing for the win even after the sacrificed bishop?

@The_Insanity_Defence if white plays Kxh2 black draws (or could play on with Bd7 with two pawns and some attacking chances for the piece, but this is risky), but if 10.Kh1! Qh4 11.Rxe4! dxe4 12.Qd8+ Qxd8 13.Nxd8+ Kxd8 14.Kxh2 he can play on. Most won't find all this OTB and if they try protect against the threats (if you look confident, they might), black will have lots of fun with his attack.

Just analyzed it with Fritz and got these lines:

White is supposed to be slightly better in this position and that's why the variation is rarely played, but I don't see why. Fritz rates it +0.2, perhaps Kramnik will make this his next drawing weapon :P

@brilliantboy: I used to think of the Smith-Morra of just another of those lame unsound gambits where you sac a center pawn for open lines and one tempo, but I've actually found it quite dangerous as black when I tried to proceed as in normal Sicilians and white plays Rd1 and e5. Will look into it.

@Conzipe: I guess you mean to play b4 next to undermine c5? I think that's too slow in regard to development and the center :P