I prefer heirloom on just about everything. That goes double for tomatoes.
I have a weird thing about colors. Purple beans, orange or purple coliflower, yellow tomatoes, black tomatoes.
Peppers, we tend to go overboard. Hot peppers, sweet peppers, cayenne peppers for the birds. Then some oddly shaped ones.
We also try and add new stuff every year, usually something we hadn't tried or something more exotic.