The games look really good on an hdtv. Not sure if Nintendo is upscaling them with hardware or software, but the pixel-perfect option for games makes them look really sharp and the pixels look really good and pixely. They don't look terrible like the iphone remakes of older games that smooths out the jaggies.
I've been enjoying Breath of Fire I, Kirby games on NES and SNES as well as all the mario games. I hope they start adding GBA and N64 and Gamecube games.