Re: what should i go for?
DS has some good games. If you never played Animal Crossing, pick that one up. I actually played it on N64 and own both, it's a lot of fun to just pick up and go actually. I also have Mario DS which was fun the second time through. I want New Super Mario Bros. and Mario vs. Donkey Kong 2, but I'm sort of broke and short on time.
Are you looking for a handheld, or just a new system in general? I'd say Wii. It's pretty cheap for what you get, and it's looking like there will be some nice titles. I'll probably end up getting one.