There isn't a member of the supporting cast on I Dream Of Jeannie who could compare with Agnes Moorhorhead, Marion Lorne, or David White, not to mention the recurring cast that included the likes of Maurice Evans, Paul Lynde, and Bernard Fox. What was Hayden Rourke? Chopped liver?
I'll be magnanimous about this. I will bow to no man in my admiration of Hayden Rorke (note the spelling Ivan - I'm just saying; I mean really Agnes Moorhorhead?) as a comedic talent, or indeed as a TV presence. He was seen in a huge number of TV shows, particularly in the 1950s, and his really active career continued well into the 1970s. Moreover, despite being best known for playing Dr. Alfred E. Bellows (and I can't help but wonder - in the light of Mad Magazine's perpetual coverboy - why they decided on the initial "E") the range of guest roles he was cast in after Jeannie wrapped up showed an impressive versatility not to mention a willingness on the part of casting directors not to typecast him as a comedic actor. But then he'd never been "just" a comedic actor before I Dream Of Jeannie before, so why should he have been after. Still I don't think you can compare Rorke as an actor to Agnes Moorhead (of course) or Marion Lorne, who was an accomplished stage actress in America and England before making her film debut in Hitchcock's Strangers On A Train. I might give you David White, although his IMDB filmography may be even more impressive than Rorke's and followed a similar path in that he tended not to be typecast. And while I'll give you Larry Hagman over Dick Sargent, Dick York kicks both their asses.
I suppose the thing that really differentiates the two shows in terms of supporting cast isn't the actors it's how they're used. The supporting cast of I Dream Of Jeannie is remarkably thin compared with Bewitched. There's Bill Dailey as Roger Healy, Rorke as Dr. Bellows and Emmeline Henry as Dr. Bellows' wife Amanda (and yes I know there's someone I'm missing - it's deliberate). It's very conventional - best friend, antagonist who sees things he can't believe and tries to prove it to the world, and his clueless wife. Think of Dr. Bellows as a male (and more active) Gladys Kravitz with Amanda as Abner (she meddles more but is more involved with meddling with Tony and Jeannie's real lives). Roger is very much a copy of Larry Tate - you know that if Larry knew about Samantha he'd be pestering her for a solid gold yacht with a platinum dinghy - but unlike Larry he doesn't have power over Tony. There's no I Dream Of Jeannie equivalent to Endora or Aunt Clara and the closest they come to a version of Uncle Arthur is Jeannie's dog, the uniform destroying Djinn-Djinn.
It's the creation of characters that marks Bewitched as a superior piece of work. Our friend Jaime J. Weinman claims the superiority of the first season of Bewitched over subsequent years in an article he wrote about Danny Arnold who was writer and producer of the first season of the show, and he's right. The first season made the gimmick incidental, which subsequent seasons didn't do, to the characters' lives. It could just as easily have been a show about a rich girl who married a working class boy, which is a model that even Samantha's father Maurice would fall into comfortably. Bewitched had characters we could identify with. Larry Tate is a mix of boss, best friend and the 1960s idea of the typical ad executive. People loved Aunt Clara - the only member of Sam's family Darrin could stand - because she reminded us of an elderly somewhat dotty and eccentric relative we all have. Even characters created after that first year have a quality we can identify with. Shake most family trees and an Uncle Arthur will fall out. The same with Serena - every family has a "wild child" like her except that in Samantha's family the wild child is closer to the norm (I recall reading somewhere that Serena as a character was a lot closer to Elizabeth Montgomery than Samantha). In short Bewitched - and specifically that first year - gave us believable characters that we could identify with. I Dream of Jeannie never had that; it was a flawed copy - in comic book terms Bizarro Bewitched - that copied the gimmick but missed the true essence of the original.
But Ivan, old buddy, you might have saved yourself - could have kept me from writing this - if you'd only mentioned one other I Dream of Jeannie actor, possibly the best of the entire cast. Ivan, how could you of all people forget to mention General Peterson himself, Barton MacLane!