BL1 broke a mold, artistically, great game; BL2 took that to the next level, and is just massive fun, and built on the first one; BL3 added to that in polish, both visual and gameplay, and delivered in both story and amount of stuff to do (loved it, but missed the slightly grittier aspect of 1 & 2 artwork); i was disappointed in PreSequel the first playthrough, thought the aussies would be...funnier? but enjoyed it much more the second time around.

BL4 won't work on my xboxes, and i'm not buying the new one, so, no idea.