Looooooooooooooooooooooooooooooooooooooooooooooong-time lurker, first-time poster.
There are MANY great guests in Bing Bong history, and I won't argue the merits of a Jessica St. Clair, Seth Morris, Adam Scott, James Adomian, Nick Kroll, Amy Poehler, Horatio Sanz, Bobby Moynihan, Ben Schwartz, Tom Lennon, Lauren Lapkis, Jon Gabrus, et al.
Or even - clutch the pearls - a Mr. Paul F. Tompkins.
But, I think my favourite combination of guests/host has got to be Jason Mantzoukas, Andy Daly and Scott Aukerman.
Holy Dinah.