One of my favorite shows of all time is Tales From The Crypt. There are many, many reasons why this is the case, but one that I'll point out is that it has guest stars, and having guest stars means a whole lot of watching and saying, "Oh hey look, it's that guy." And when you say that, everyone in the room goes, "Oh yeah! That guy!" Everyone knows who you're talking about, even when nobody knows the actor's name.
So I'm curious: who is your "that guy?" Tell us a story about one of your favorite "that guy" moments, and vote for your favorite webcomic after the break.
Penny Arcade (Chronomancy)
Awkward Zombie (Making the Cut)
ActionTrip (Corporate Strategies)
Critical Miss (The Labels)
ReadySoup (Some Drink to Forget)
The Gamercat (Super Meowio World)
Hejibits (Karpe Die-m)