Nimzo-Larsen Attack with 1.Nf3. I really like it because, no matter what black plays, it's still the Nimzo Larsen. This means that white is usually prepared for whatever black throws out. There are no trick lines or gambits with mountains of theory. Speaking of theory, there isn't much on the N-L and it's really easy to understand. It took me just a couple days to learn the theory! Also, the knight on f3 and the bishop on b2 do a great job of complementing each other; They both control d4 and, most importantly, e5. Still, it was a tough choice between this and the King's Gambit.
Favorite Opening?

As white, 1. Nf3. I don't pre-think my openings any farther than that!
As black, I have no preference - it entirely depends on what my opponent plays, and probably what kind of mood I'm in.

My favorite opening is Queen's Gambit (Declined or Accepted) transposed from a first move 1. Nf3
Nf6 2. d4 d5 3. c4 or 1. Nf3 d5 2. d4 e6 3. c4after i analyzed, fischer-karpov-kasparov, so.. i can analyzed my character. might be - dot matrix player white lion - that's me. so i make the nickname for opening, i called black market - dismarket, with the amazing variant and the nickname is dragon. but i still lose, may be rule patience or the other variant. so, i still analyzed until perfectly, because of eight variant. my variant in knight, right-left, bishop, and may be till root. so, i still confused in opening, thank you.

As White i like to play against the Two Knights. 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Bc4 Nf6 5.e5 d5 6.Bb5 Ne4 7.Nxd4 Bd7 8.Bxc6 bxc6 9.0-0 (There are other move orders)
As Black i like to play the English defence.
What's your favorite opening and why? Also show a picture of it or the moves list for some of us who don't know what it is. Becuase you shouldn't expect everyone to know all the openings.