Just because S3 makes me want to beat the LnC Costume designer over the head with a stick...
Most hated: the outfit she wore when she was in the alternate universe. Gah! The tapered pant legs, the vest looking sweater thing, the continuous color, the hair, the bright lipstick...ugh! I HATED that whole mess!
Runners up: I wasn't too crazy about the red suit and - was it leopard print? - scarf from "Contact". Or that blue suit with the green inside shirt and those giant green earrings...speaking off which, what was up with all the giant earrings in that season?! Seriously, why?! And that orange suit with the random white trim that looked like giant stitches or something...The shiny suit...eh...I wasn't as opposed to that as some, but the shiny undershirt from COTOC (?) was a much better use of shiny clothes. And what the crap was that dress she wore to the white orchid ball? When Clark floated, I was like "that has to be love, b/c that is the most hideous dress I have ever seen." Why in God's name did she own it and think it was appropriate at any time resembeling the present day?
