If money isnt a problem, I say wait for the Wii. Twilight Princess is coming out along with it, and other games such as the newest Super Smash Brothers have already been confirmed. In addition to this, it will have backwards compatability with the gamecube, and I think N64? Also, if it isnt compatable with N64 games, I do know you'll be able to download them off the internet, I guess sort of like Itunes. SNES and Genesis games will also be downloadable...so even if there isnt much coming out for it to start, there will be a lot to get, I would imagine. It also seems to be the most anticipated system on sites such as gamefaqs.
Don't get me wrong, the DS is also pretty fun, but a lot of the games seem like GBA games with gimicks to make use of the touch screen.