I just downloaded the Sacrifice demo and it's REALLY fun, especially if you like FPS/RTS games like Battlezone. That and American McGee's Alice are both on my Xmas list. =)
I would have to give BG2 a definite THUMBS UP. It kicks so much ass. True it's not exactly the most cutting edge game out there and will probably tax your system just slightly more than MS Word, but man, the storyline is FANTASTIC and the gameplay is phenomenal. It'll give you some 2 billion hours of playtime too, give or take.