Seth's Joker is the best character in Mass Effect 2! (spoiler)
Playing through Mass Effect 2 and I just did the section where you take Joker to the AI Core. I know alot of the coolness here is on account of the great job Bioware did with the game and stuff, but Seths voiceover really is the icing on the cake. It's without doubt the best sequence in a game full of awesome sequences and that's thanks to him making Joker genuine. You really don't want to see his frail bones get busted up.
"*beep*"
"*beep* *beep* *beep* *beep* *beep*"
"*beep* *beep*"
Pretty much swearing from the cockpit down to engineering :P I felt so bad for the poor guy.
And his line when he reaches the AI. Wicked!