I'm looking at a leftover LT with the 3.42 rear end and a Yukon with a 3.08 rear end.
I have 3.42 gears, granted mine is a bit older, and they suck ass for towing. That was before I went to a bigger tire, making them even worse. Unless you like driving around in 2nd gear all the time - including some hills out on highway/freeway - I'd go min 3.73's.
Old enough to know better, young enough to do it anyway.