Hi, I am trying to learn Caro-Kann watching Karpov's games, but who are the famous or less famous GMs who play or played Caro-kann with good results?

Korchnoi,Petrosian,Smyslov,Capablanca,Flohr,Botvin nik

Not sure about the modern players.

There is an old book on Alekhine (The Young Alekhine) by Fine.
It appears that Alekhine had to learn what he could and could not play.
The Caro-Kann was one of the openings he learned to avoid playing.
Beside the above, NImzovitch can be added. Keres gave the opening a try a few times. See Maroczy-Keres, Zandvoort, 1936. Reti also tried it. Note that the Queen's Gambit Accepted can transfer into the Caro-Kann. See also games by Tartakower.

Jon Speelman and Yasser Seirawan played it frequently.

Speaking of the Caro-Kann there's a line where black plays c5 on or about move 4/5. I can't play that. I feel like I wasted a tempo. Does anyone here play it? Anyone agree with me? thanks

I used to think it was a move designed solely for blitz play. Someone managed to convince me otherwise showing me who was advertising it (Nunn I think).

1. e4 c6 2. d4 d5 3. e5 c5!?

I couldn't play it either, I don't believe in it. In fact, I'd rather play that odd line in the Alekhine, 1. e4 Nf6 2. e5 Ng8?

LOL I agree, gang! Most of my cronies call it the Caro-Can't. While there are, of course, some folks who have had success with it, I am sure not one of them!

Lasker's Manual of Chess (Paperback)
An updated version.
Amazon.com will have the book in January 2009.
Cost: Way cheaper than the list price sold by Chess stores.
See: Lasker's Manual of Chess - USCF Sales

The same goes for
St. Petersburg 1909: The Famous Tournament Book by the Second World Chess Champion (Paperback)
by Emanuel Lasker (Author)
Not the original version of this book taught the young Alekhine. Lasker wrote the notes to each game.

I have played it to some success, but if you're not careful, it does lead to some very passives game for black