For daily-driver burgers, I use the chuck/sirloin 85 patties from BJs. Sprinkle on a bit of Penzey's Northwoods spice, grill 'em on charcoal.. rare to medium-rare.
Grill the bun, add a slice of Vermont Cheddar, lettuce, tomato, and a dab of basil pesto.
There are a few butcher shops (and one chain) around here that make their own hand-formed burgers. And they are quite good. But I find having a good source of frozen patties makes it much more likely that I'll actually grill a few up. Also, frozen patties are easier to get to the crisp-on-the-outside-rare-on-the-inside state