I try to keep my burger on the edge of the grill when I cook for my wife and two step-sons so I get medium rare, but that's not possible with the factory-made burgers -- they're not nearly as tasty, but they are way less work.

My latest batch of hand-made burgers contained diced onion and garlic, along with oregano, paprika, chili powder, pepper and salt. They fell apart a little on the grill (perhaps an egg as binder next time) but tasted great.