u should check beyondyou, akari_un, aafyre, johnclb, and im probably forgetting sum of the vertex gods...
seriously, aafyre has probably got the best vertex hacks around...
Speaking of which, Banjo and Kazooie could replace Mario. The desire for a PSA is so high that it's pretty much guaranteed to be made; however, it does need some color options.
If Aafyre's okay with it then Banjo would be great for Mario.