Dinosaur Jr/J Mascis has to be up there, especially when factoring in how many iconic parts/videos it's used in.
Doubt they are near the most used, but De La Soul is used in three very iconic parts (Carroll in Ftc-Finally and Goldfish, and in Daewon's New World Order part).
Elliott Smith seems to get used a lot in recent times starting with Nate Broussard in Static 3, but also BDK's welcome to DC part, Suciu's Cross Continental and Dylan's Mindfield part.