This is one of the best episodes for Season 3 and it's a very memorable one at that. It's the one where Michael sends out 4 teams of 2 out on sales calls, which gives Andy plenty of time to try and undermine Dwight by pointing out his flaws to Michael. Apparently it works because by the end of the day, Dwight has resigned and ends up working for Staples. This episode is also notable for 2 other reasons. A) This is the one where Jim pranks Andy using his Cell Phone as the instigator, which causes Andy to snap emotionally and punch a wall and B) Jim admits to Karen that he still has feelings for Pam.

Also, Oscar returns back to the Office full time. Just a heads up for those not good with remembering things, The Office would revisit Andy punching a wall in Season 8 with the episode Angry Andy