Okay, here are my least favorites, in descending order:
-Neelix (actually, he and Weasley were tied for first place, but Neelix edges out front by just a bit)
-Wesley (PLEASE don't get me started)
-Janeway
-Troi
-LaForge (anybody who mouths off to the man who's forgotten more about engineering than he'll ever learn in a lifetime, well... )
-Barclay
-Seven (cleavage and a bad attitude do not a good character make)
-Rom
-Picard
-Data (Spiner's talented, but the role never expanded enough to show his range and he fell back on the same old routines)
-Christine Chapel