I've been putting off my play through Super Mario Galaxy and Super Mario 64, but I managed to complete my favorite two Mario games a 100%, Super Mario World and Super Mario Sunshine.
I may want to get back to Galaxy and 64, but I just started a new playthrough of Twilight Princess HD, and I made it into the first dungeon, I also have a playthrough of Chrono Trigger to get back on when I have time.
Finally, I'm thinking about starting another playthrough of SpongeBob SquarePants: Battle for Bikini Bottom again. Also, I'm in the middle of a playthrough of Paper Mario: The Thousand-Year Door.
Other than that, I'm trying to get enough pokeballs to catch everything in Pokémon Crystal, and I'm waiting for a good time to play Paper Mario with @Princess Niki.