How did Victreebel find its way onto the poll? It's more cool than anything. :D
Let's see, Feebas and Purugly are intentionally ugly, so I'm not even considering them. Weezing, Glalie, Koffing, and Grimer are actually kinda cool in terms of their design.
That leaves Jynx, which just plain freaks people out and changing her skin to be purple just made her look unnaturally creepy.