Battlebots (PS2) - Loved the showed and I couldn't wait for the game, but when both were cancelled. I played the GBA version, but I wanted the console version.
Shenmue 2 (US DC) - Cancelled weeks before the game was to be released and moved to the Xbox. I know there's the Euro version, no US version was disappointing.
Black and White (any console) - Rumors and pics came about for this game on the PS1, DC, and PS2 and nothing came about after a few months of nothing. There are handheld versions coming on the PSP and DS, but that may just be a tease, as well.
True Fantasy Live Online (Xbox) - Everything Level 5 touches turns to gold, so I'm saddened about the MMO that got away, at least for now.
Pipo Saru 2001 (Ape Escape 2001) - The first AE PS2 effort that had Spike vacuuming pants off of the monkeys instead of capturing them to wash the pants. I'm always up for more Ape Escape and this sounded like so much fun.