Yeah I agree with AMD being the best for gaming
If you were to do alot of tasks that need multi-tasking as well, I'd say to go for an Intel, since I find sometimes that the AMD doesn't give me enough power for this type of thing (When I'm running alot of programs at once). If you have some good memory to help though, then this definitely speeds things up
but yeah, theres nothing wrong with AMD for this also, and as long as gaming is a big thing, AMD is so much better.
I agree on that card to 99nasha suggests. Its powerful for games out at the moment, and will be for a while i'd think. Plus its a nice cheap but effective card for your cash
Also, dont get tricked into thinking a AMD Athon 64 3000+ running at 2.0ghz (i think) isn't as good as a 3.0ghz Pentium, since you'd be wrong. AMD uses a different type of structure where more processes gets done in each clock, maximising performance, so can easily match and be better than a Pentium clocked at 3.0ghz
Hope this helps