I'm currently using 1...Nf6 as it forces white to defend his pawn and stops him playing the game he wanted to. 

...c5 is the only response as far as I know.

I could play e6, or c6 Nc6 but really if someone wants to start out with e4, I'll take their challenge with e5 as their are so many variations after that.. and there is no better feeling than to crush your oponents strongest opening.. if possible.

I wont play c5 btw because i think its terribly slow and leads to a boring game.

well. in individual games i have tried any response (a5,h5,b5 excluded for stupidity) but my "natural" impulse nowdays is the french e6. i never tried studying any opening so intensively... not that i study the french intensively. :)

hey  i'm not folowing statistics it seams :)
I rather play e6 later it might become e5, but first i think about strong defense.
in which my queen might help. Attack will folow later, altough one might try to interupts white attack but with only e4 i'm not sure which attack he will gonna play, so i let him play and look on how to adapt while plaing defensive. (as a lot of attack have e4 in common).

e6 french but white tends to exchange right away. Assumes I know the lines I suppose.

d6 pirc is fun but I keep getting BE3 BD3 BD2 all mixed up.

gonna have to say e5...

i would go e5 then d6 to start stonwall attack!!!!!!!!

how about d6?

or some obscene beginner's routine? lik 1. e4 a5. lol

Nf6, d6, or e5

 No question about it....

1. e4

1.--c5

there is nothing better in my opinion, if black wants to win

If blacks plans to draw?

1.--c6

or

1.--e5

Laugh hysterically and try to freak him out!

My favorite response is actually 1...e6; heading into a French Defence. This opening has always been a favorite of mine, and I find that Black can get good piece play in exchange for a somewhat cramped queen's bishop. In particular, c5 pawn breaks and good knight play are trademarks of a French Defence, so it suits my style.

1...c5 is also quite fun to try out, although it is vastly complex and almost too popular at my club.

1...c6, a Caro-Kann, used to be my favorite defence for quite some time, but I've been having big problems with some of Black's lines that give White too much space. It will stay up on the shelf until I find some suitable counters.

1...e5 is solid, but somewhat dreary. I play it when I simply can't think of what else to play. (Since I am familiar with many of its lines.)

1...d5 is awful. Never touch it.

1...Nf6 is fun for me to try out sometimes. I use it a surprise weapon when I'm playing a game I don't absolutely have to win.

i would go for e5

1...d5

c5

im a big fan of alekhines ... 1. ...Nf6. that said ive been playing french alot lately. its extra sharp! :)

Always e6, although I'm checking out the main lines of c5 at present. Probably will stick with e6 forever though - I've invested a lot of time learning lines and it gives me solidity and enough counter-chances.

Tally so far reads:

Nc6 - 1

E5 - 9

Nf6 - 6

C5 - 9

D6 - 4

E6 - 7

A7 - 1

B6 - 1

C6 - 3

G6 - 2

D5 - 5

Nh6 - 1

Laugh Hysterically and try to freak him out - 1

Big fan of 1...e5.