which do you reccomend
which is better the semi-slav or slav

I like 5.e3 a6 in the Semi-Slav. If your opponent doesn't know what they are doing, it's easy for Black to leave the opening with an advantage (the idea is to take on c4, play b5, and play Nc6, which is impossible after the usual Nbd7). The correct moves for White are generally considered to be 6.b3 and 6.c5. If you learn the replies to all of the wrong moves, and why they work, this is a useful weapon. I have very good results in this line.
The Cambridge Springs defense (5.Bg5 Nbd7 6.e3 Qa5 in the Semi-Slav, technically a line of the Queen's Gambit Declined that originally used to arise by the 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Nbd7 move-order with 5.Nf3 c6 6.e3 Qa5) is a good weapon, also 5...h6 is what I play. 5...dxc4 is very risky and well-analyzed; I wouldn't recommend it to anyone below master level.
Overall my vote goes to the Semi-Slav. I don't think it really requires as much theory knowledge as the Slav, having played both at 1500-1900 club level before advancing to the 2000+ stage, but what do I know.

nice games I'm playing one right now here is a link http://www.chess.com/echess/game?id=57802390 if you want discuss it go ahead but don't give hints on future moves because at the moment it isn't finished and I don't want to be accused of cheating

Ahh, I remember the famous Topalov-Kramnik 2006 World Championship, where they played queen's gambit declined lines. Please look at those games it should be helpful.
Here's a link for my famous one: http://www.chess.com/games/view?id=1372429

Except about the move-order, 8...Bb7 is actually the most common move right away with a6 coming later.

For me Semi Slav is the best.If you really want to win the game with black then choose semi slav,if you are playing for equality then go for slav.See Anands world champ match against Topalov and Kramnik.He chose slav just to hold the game with black.

pellik, the lines with b3 generally don't involve an early Nc3 so White doesn't really make that choice? Unless you're talking about a different line, but when I think of a setup with b3 against the Semi-Slav, I think about this:
As posted, Black has additional options if White plays this way, and if White plays Nc3 and b3, his Knight on c3 is misplaced.
Both the semi-slav and slav are played against the queen's gambit declined lines, but which one is better. They both got their pros and cons. The semi-slav is a solid opening, but it blocks the bishop in, so it will not be able to come out for a while. On the other hand the slav opts to let out the bishop though it often becomes a target. So which is better, I think the semi-slav
SEMI-SLAV
SLAV