This is taken from a rapid game where my opponent threw me by playing 8. g3, coming out of book in the 4. e3 Slav:
[FEN ""] [StartPly "17"] 1. Nf3 Nf6 2. c4 c6 3. d4 d5 4. e3 Bf5 5. Nc3 e6 6. Nh4 Bg6 7. Nxg6 hxg6 8. g3
I didn't keep a gamescore (it was at work during a lunch break), but I remember at this point I could think of no constructive plan at all (I played 8...Bb4 and ended up playing 2 knights vs. 2 bishops with a cramped game).
My question is, what should black have played on move 8 and why?