My standard is Wegmans Lump charcoal and it's very good,burns evenly,a good distribution of lump sizes and fairly priced
Green Egg lump is very good but costly so I only used the initial bag I got with my BGE
The worst is Cowboy brand, holy crap I actually have sticks and whole pieces of log in the bag. I picked up a 20 lb bag at Lowes on sale for $7.99, now I know why it was so cheap. Just fired up there BGE and put 2 racks of ribs on so I'll see how it actually burns