3. Brian Fantana - Anchorman: The Legend Of Ron Burgundy (2003)
A large bulk of Rudd's filmography involves him playing dudes that are as handsome and naturally endearing as he is. One of the major exceptions is Brian Fantana, field reporter, namer of testicles and lover of aftershave from improvised comedy Anchorman. The improvised part is important. Both Anchorman films had loose structures, but the lion's share of the dialogue and jokes are come up with on the fly. Which means not only did Rudd play Fantana to a tee, but he basically invented the character and all of his best lines. The shaggy-haired, misogynistic, idiot wannabe-lady's-man is about as far from Rudd's usual wheelhouse as its possible to get, and he still nails it. The whole Sex Panther episode probably would've worked whoever was wearing the Bigfoot-genitalia-smelling scent, but it was Rudd who cooked up and really sold the idea.
Tom Baker is the Comics Editor at WhatCulture! He's heard all the Doctor Who jokes, but not many about Randall and Hopkirk. He also blogs at http://communibearsilostate.wordpress.com/