All these games(especially the sonic ones, both 2d and 3d) textures look very low resolution and would be helped a lot by a texture pack.
Sonic Adventure DX (or maybe the PC version should be retextured instead?)
Sonic Adventure 2 battle
Sonic Mega Collection
Sonic Gems collection
Tales of Symphonia(the ground looked low resolution, even on a real gamecube at 480i)
Burnout 2 could use some better road textures, maybe burnout 1 also
New Super Mario Bros Wii
Super Mario Sunshine
Skies of Arcadia Legends
possibly SSBM/SSBB(I haven't played either in a long time and don't remember how good/bad their textures look)
The Wii textures are ok, but far from great. Not all of them need enhancing but some are very low and these games are just amazing: they deserve better (SMG 1/2, MP3), especially some great particle effects and an improved HUD so that one can enjoy these games in HD without hving to put with thw washed out interface.