I'll start. Right now I'm playing lots of Picross on the SNES (working on MSP and NP 1 and 2 at the moment), some occasional Bejeweled 2 (trying to get through Endless, hehe), all four GH games on PS2, and a total of nine DS games (Picross DS, Neves, Puzzle Quest, Yoshi's Island DS, New Super Mario Bros., Kirby: Squeak Squad, Chibi-Robo: Park Patrol, Clubhouse Games, and Nervous Brickdown).
Also, on the back burner at the moment, are Super Mario Sunshine (trying to get all those blue coins), the first three Katamari games (trying to find everything), Polarium Advance (trying to finish all the puzzles), Chu Chu Rocket! (also trying to finish the puzzles), and FFV Advance (trying to level up every job to max, get every spell, and complete the bestiary).
Yeah, I'm hopeless. How 'bout you all?