I think at club level and perhaps quite a bit above ...c5 is a good move. You may get a couple of people who slavishly follow master praxis "frown" at your defence.
White will usually play d5 if he is ambitious or 1e4 c5 2e3 or c3 if he is a wet blanket, but what is effectively a subvariation you give is fine for black IMHO.
Ah. I knew I had made a mistake somewhere.
I think it's best just to stick with the tried & tested 'main' responses to d4 - e.g. just play 1. ...Nf3 2.c4 e6 then if he plays 3. Nc3 just play Bb4 and go into a Nimzo-Indian and if he plays 3. Nf3 play 3. ...b6 and go into a Queen's Indian (check out the main lines in game explorer). The only problem is that 1. d4 players are likely to have prepared these lines a lot, but I think at our level it's best to play the solid main lines rather than trying to come up with something clever.
go for something simple that you can play your whole life. If you like to attack with black you can try the Kingsindian defence. If you want to have a solid game, d5 is definetly the right move for you.
The Nimzo Indian is not THE MAIN response to 1.d4 at all.
THere are many mainstream responses to 1.d4, not any single one of them can claim THE MAIN response to "1.d4".
1.d4 d5 is every bit as main as is gets compared to anything.
The Dutch is also main.
The KID is main.
The modern is also main now days.
My suggestion is to find a training or educational material and start studying and applying.
As you get experience, you will adapt and overcome.
I wasn't saying the lines i suggested were the SINGLE main lines for 1. d4 (note how i said "e.g" not "i.e."). Of course 1. d5 is main, assuming you follow it up correctly. But if you play 1. ...Nf3 then KID/QID/NID are very important lines you need to know (and just as mainstream as any other), just as if you play 1. ...d5 you should know about the slav, QGD etc.
To the OP...
Countless numbers of books have been written on this subject. There is no way this forum/we can give a remotely adequate answer. If I was you I'd buy a book - or just scout one of the online databases (there is one on chess.com as well) and see how it can be played. Having said that, the most common answer by Black is 1...Nf6 and 1...d5
The Mexican defense is very effective.
1...c5 is ok. White usually gets a good game after d5 and putting the knight on c3 but you can play this way. I think 2.e4 is tricky because you could get move-ordered into something else.
i usually play this
can you tell me a better move ? i would be very happy :)