The Bard's Tale (actually, I think that's a port from the PC version - it has higher-res textures than the PS2 version.)
Grand Theft Auto III (same deal - looks a little sharper than the PS2 version though it has draw distance issues.)
Shadowgun THD and Mass Effect: Infiltrator both look great and play well.
Square-Enix has been rereleasing the Playstation upgraded ports of Final Fantasy games for Android. They don't push the hardware much, of course, but they're 'PS1 quality'.
And I had a really fun 'attack the castles' game I forget the name of. (I don't have my tablet handy.) Siegecraft HD, maybe? I remember it had standard and Tegra-optimized versions for sale.