I liked Kirk's short-sleeved tunic and admiral's uniform, but the colors were blah.
I also liked McCoy's 'leisure suit' variant. Kelley seemed to favor that style in real life too, though it would have been better with his ascot or bandanna.
The built-in boots made for a sleek look, but TNG did it better with the stirrup thing.
I could have done without the rodeo buckle, but it did break up the long line of the tunic.