* Adam Scott has been the most frequent face of Nerd, playing a variety of characters including the "Nerd Guy" and "The Nerd" in multiple commercials.
* Martin Starr has also appeared in several Nerd commercials, notably as a character named "Steve" in a series of ads that played on his portrayal of "Bill" on the show "Freaks and Geeks."
* Other actors: Many other actors have appeared in Nerd commercials, including Tim Heidecker, Eric Andre, and a variety of other comedians.
It's worth noting that Nerd commercials often feature a revolving door of actors and characters, so it's hard to pinpoint any one individual as "the Nerd" in the same way that you might identify characters like the Geico Gecko or the Aflac Duck.