Who makes the best one? It might be one of these
I'll know pretty soon cause I ordered one about a week ago. What can I say, I'm a gadget freak!
I have a couple of these
and they look pretty good on a scope
but you have to raise your head to see the bubble. Works to train you to shoot with the reticles level and would help if you had time to set up a shot in the field.
I'm not sure about one that would be bulkier like the scoplevel or stick out like the USOptics. Might snag something and would be hard to case.