Star Fox Wii with both flight and on-foot gameplay. Massive scale flight maps in which you're not stuck to a rail. Could have IR aiming for Arwing, and maybe Arwing melee combat. (barrel roll can be used as a weapon? Speed Racer esque body slams and side ramming, Sonic esque homing attacks..)
Mega Man Powered Up 2, with a level download manager and archiver. Be able to download multiple levels at once and be able to have hundreds of levels, not just 30. Be able to leave comments on levels. (optional: gamers will be able to do this on the computer and not just the PSP) Game would keep track of whether or not you've played a level before and whether you've beaten it.
The Orange Box for Wii
Ridge Racer 8, drawing inspiration from Speed Racer movie, more psychadelic, with corkscrews and stuff. Maybe could throw back to Rally-X and have smokescreens and oil traps.
Ridge Racer Wii (either above, or a Ridge Racer 7 port)
codename Mega Man Galaxy (IR aiming in the style of Mario Galaxy, except that the shots actually come from Mega Man, i.e. you can make him shoot at the foreground. Planetoid levels are fine too, would fit Mega Man excellently, including bosses like Astro Man and Galaxy Man. Could be a shine hunt like Mario, really this is exactly what MM needs. Star Force Mega Man could also be playable, and would ride EM raves kinda like Mario flies through space. Bass obviously playable as well!)
Mega Man Star Force Wii. 3D superhero sandbox game with card system from Network Transmission and cinematic fully voiced anime presentation and graphics style. Possibly a lock-on combat system.
Professor Layton Wii. Alternates between two gameplay styles. Outdoors, you control Layton directly kinda like Shenmue. Indoor, it's point and click, but not first person, Layton is seen rummaging around and pondering while you make your selection. (optional: third person shooting segments in the style of Gears of War)
Sonic Adventure 2 remake with, among many other updates, more Sonic and Shadow stages. PS2 is choice. (and/or Wii, PSP, PSN/XBL)
Sonic The Hedgehog PS360 remake for Wii, PSP, and/or XBLA and PSN. Changes include, among other things, Arcade mode, online multiplayer, and normal Sonic gameplay to replace instances of snowboarding and Elise.
Sonic Unleashed Director's Cut that includes, among other changes and additions, an Arcade mode and a slew of additional characters you can play as namely Knuckles, Blaze,and Amy. Wii/PS2 version would have Empire City and Mazuri added to it.
Sonic Unleashed PSP
Shadow the Hedgehog PSP Remix. Better control, Alternate Playable Characters (including.... Sonic maybe??) and new presentation/marketing/boxart using
that 2D Sonic artwork style. And new stages. As far as maybe Sonic could have 25 completely unique stages in the same game engine.
Street Fighter 4 Wii, PS2, PSP?
Stunt Race FX Wii
Command & Conquer Wii
Daytona USA 2 on any platform considering it was never released outside of Arcade. PSN/XBLA/PS2?
Little Big Planet PSP
Castlevania Judgement 2, but this time it would be a full fledged action RPG -or- co-op beatemup.
Magic the Gathering Wii, PSN, PSP, seeing as MtG for XBLA is coming out. Also next Yugioh XBLA, Duel Masterx XBLA, World of Warcraft TCG XBLA, Pokemon TCG XBLA... oh wait.
Mario Party 9
Castlevania Party
PSP2, or PSP Touch Mini (not games, but hey)