I played the slim at my friends house. It made much less noise then a normal one, never crashed for us while playing at all.
Also, the games we played were S&SRWBK (Sonic and sega racing with banjo-kazooie), Bad company, GTA 4, ...that expansion with the motor guys, I forgot the title right now, and Gay tony.
Maybe ours is good, or something is wrong with yours. I was thinking about buying a Slim for a while now already, and this goes against any experience I had with the Slim's I played O.o