Knowing I wouldn't use a bike rack a lot, I bought an Allen 530RR from Costco for about $100. I knew if I didn't like it I could return it hassle free. It's actually a pretty decent 4 bike rack with a special bolt that keeps the hitch tightly connected. I only carry one bike and it works fine and doesn't rattle.

There are many better racks out there, I'm sure, but you pay a lot more for them.