My main reason for being excited about the Wii is for the online mode for the new Super Smash Bros Brawl game. As a member of a Legend of Zelda forum, I have a lot of friends anxious for this and a lot of people to settle some scores with in some nice Nintendo battles. Gonna be some good times.
As for the DS: Mario Kart and Animal Crossing are amazing games. I'm waiting to start my job in a few weeks before I can buy more games like New Super Mario Bros and Metroid Prime, but as far as third party games go, TMNT3: Mutant Nightmare and Pirates of the Carribean: Dead Man's Chest are awesome games with local multi-card co-op modes. Super Mario 64 DS is pretty fun, too (my friend owns it and I tried it), but I can't wait for Diddy Kong Racing and Star Fox to be released.