The Danza: All cast and characters except Jason, because Jon Benjamin already plays John McGuirk, with Paula becoming a later exception (her UPN run being voiced by Paula Poundstone, her Adult Swim run being voiced by Janine Ditullo).
Hey, It's That Voice!: Only after watching this show, Archer, and Bob's Burgers do you realize that H. Jon Benjamin's vocal range is very limited (and that you can't stop picturing Coach McGuirk as Archer or Bob).
Though you may be surprised to learn he also plays Jason
Comedian Louis C.K. is the voice of Brendon's father.
The Other Darrin: Paula. Played by Paula Poundstone in the first 5 episodes (the ones that aired on UPN). Then, when the show was Un-Cancelled and put on Cartoon Network, she was played by Janine Ditullio for the remainder of the series.