It really depends what you want to do with your laptop as to what kind of spec you need. Yeah, kinda obvious, I know, but it bears repeating.
I mean, I use my Macbook for writing and surfing. The only things I'd want to put on it, in terms of games, are emulators, but since they're... dodgy, I haven't and I'm not going to. [I might possibly get CIV IV, but that's about it.] Oh, my mistake, I play Doom. No, not doom III, just the OSX version of Doom.
Oh, and I watch Chii's Sweet Home on it as well. And use it to get music on to my iPod.
[For games, I have my PS, Xbox 360, and DS, which I'm playing Final Fantasy VI on...] [I really must check out the old games on XBox Live]