So the group description says these guys have been around for 5 years, but even that only stretches back to about the Awesometown/start of SNL era (Samberg joined the cast in the 2005-2006 season. Actually, Awesometown was made early 2005, and if it had been picked up for a series, it would've debuted that season).
What's your favorite stuff from before then? The Lonely Island's (old) website actually has a lot of broken links since their Incredibad-inspired redesign, but they did a lot of shit ever since 2001 which is up by them or others on YouTube. The Quickie shorts (I love Lethal Objection), the two low-budget sitcom pilots (one has Kal Penn, the other debuted Stork Patrol), Just 2 Guyz, The 'Bu, and they wrote for the better years of the MTV Movie Awards (Lohan, Fallon) and G-Phoria.