In addition to more of Jesse Ventura and Tiger Woods, and return visits from great guests like Hamm, Oswalt, and Gould, and aside from some obvious possibilities like Louis C.K., Paul Rudd, David Cross, and Will Ferrell (who I'm sure the Sklars have tried hard to get), I'd love:
*Scott Van Pelt
*John Krasinski
*Ray Ratto (a brief phoner at top, maybe when a Bay Area sports story is in the news)
*Rob Riggle
*Jon Benjamin
*Craig Robinson
*Rich Eisen
*Mindy Kaling
*The Sklar Brothers' Mom (maybe just a phoner)
*Amare Stoudemire (maybe just a phoner)
*Steve Nash
*Detlef Schrempf (he's got the funny name, he's been the subject of an indie rock song, and based on his brief appearances on PARKS & REC he seems to have nice comedic instincts and an appreciation for comedy)