I've heard Best Show references. There are multiple tidbits that can be found in the episode with the shock jock ("zung", "toilet talk"). I know I've definitely heard someone call someone else "soft-serve". In a Halloween episode, a kid asks for peanut chews. Nothing really overt, but little words and phrases that are used fairly often on the show.
TE, can I please point out that the scenario I assume you meant, where Andy Richter and Monk become friends, is far less interesting than if Andy Richter became friends of Munch, the detective from shows like Homicide and Law & Order: Special Victims Unit?