DrakeFox: I'd have to go with Duke too. Don't think Riddick has that many good one-liners.
Also a bit of a comparison, Riddick being the guy you don't realise is an immediate threat till he kills you, vs. mr. subtle himself: Duke nukem, who'll come barging through your door shouting one liners with a bloody cannon under each arm.
Then again, only watched each of the riddick movies once, completed Escape from Butcher Bay once and never got started on Dark Athena, but there weren't that many one-liners in that game.
Perhaps, but it's all in the TIMING....
Whereas Duke is just.... Well, witty for the first time but then it's just *SHUT THE FUCK UP AND KILL ME ALREADY!!!!!!!!!!!!!!!*