-I'd like some extent of customization for the main character. Pick a trainer class, choose from a few hair styles and clothing combinations. Doesn't need to be too complicated.
-Very very rarely (like shiny rare), run into a randomly generated rare pokemon who has been partially trained and abandoned. Their happiness will be pretty much non-existant and harder to raise up. Maybe some distinguishing marks, like scars or old collars or something.
-More unusual type combinations, yes.
-More dark, poison, and fire pokemon...which is totally my self-indulgence talking because they are my favorite types.
And finally, I like being able to take my Pokemon games with me wherever I go, and being on a major system would hinder that. Not to mention there's a lot of people in my household at the moment, and I can't tie up the television like that.