All biomes, at least most. Definitely a jungle biome. Extreme hills would be nice too to get emeralds. I don't like many dungeons but abandoned mineshafts are cool. I would also like an area good for building a nice big house, but I can make anything work. I also enjoy the company of at least a few villages. I know it sounds like a tall order but I know someone out there has to have something good.
A well balanced all around good seed