I don't understand why animated characters NEED to have such annoying/unrealistic voices

YES! Dr. Katz! Thank you, that is a great example. I loved that show. I watched it as a kid, and then later got the DVDs (got hit hard with 90s MTV nostalgia.) Great show.

As others have noted, Huckleberry Hound is southern – it’s actually a pretty gentle Southern Drawl – there are much more pronounced southern accents out there.

What’s interesting is that this is the very same voice that actor Daws Butler used for his previous characters at MGM studios, before Hannah-Barbera got started. He was obviously comfortable with it.
I can’t think of any cartoon characters with New England accents, but plenty of Southern ones. There’s no good reason why not. Imagine a cartoon dog that sounds like David Ogden Steirs’ Charles Emerson Winchester from MASH*.

What was that accent supposed to be anyway? It sounded to me like Winchester was trying to be English.

It was supposed to be Boston Brahmin, Beacon Hill accent. I thought he did a pretty good job, without overplaying it. Steirs doesn’t have a Boston accent normally – listen to him as Cogsworth in Beauty and the Beast, or in any of his other roles.
On the other hand, he didn’t have the really broad Boston accent that some people I know have. His is “upper crust”.

I think a lot of why Pixar is so great and successful is because they DON’T have the voice actors doing cartoony character voices. They are straight up voices of the actor.
Craig T. Nelson and Holly Hunter didn’t try to create silly voices for their characters, they played them straight up. Same with Billy Crystal - John Goodman, Tom Hanks - Tim Allen, etc.
It fits very well with Pixar’s style and the movies wouldn’t be the same if everyone was trying to make unique silly character voices.

Yes, yes, this is exactly right. I like Pixar movies (except for Cars, which is crap.) This is a great example of how animation does not need to have those silly voices.

Except that’s not quite true. Tom Hanks as Woody doesn’t sound exactly like Tom Hanks on a talk show. Tim Allen as Buzz Lightyear sounds very different from Tim Allen as himself. They may not be quite as exaggerated as Peter Griffin or Huckleberry Hound, but the actors did go to some effort to create unique character voices.

Yes. Buzz isn’t Tim Allen, he’s Tim Allen in a deeper, manlier register.

As for the Incredibles, they wanted to portray a realistic family as much as possible. And even then Sarah Vowell’s voice is holy crap annoying, real or not. I was shocked when I saw her on the Daily Show and that same absurd voice came out. (Disclaimer: I have nothing against her herself and I know she didn’t choose that voice. That doesn’t lessen the annoyance factor.)

I will say Pixar certainly does a fantastic job of matching voice to character such that little derivation is needed, but they also have the budget to do so, and it’s not 100% normal voices anyway.

That’s true, but also note that the animation in Jon Benjamin cartoons is very restrained, almost static. Archer is a bit more dynamic, but still pretty stiff. The visuals in these shows are almost an after thought - you could listen to the audio track for a show without any visuals at all, and still get almost all of the humor.

I haven’t seen that many Pixar movies, but I know Edna’s voice in The Incredibles is pretty silly and so is Bob’s boss - although Wallace Shawn usually sounds like that; if you don’t want someone who sounds like that, you don’t bring him in. I suspect if we went down the whole list of Pixar movies we’d find a few silly voices each, mostly in character roles, which is what you find in a lot of regular movies. Maybe Roz in Monsters Inc. would be on the list.

The bottom line is that Pixar movies and older cartoons are very different. A naturalistic voice wouldn’t work for Homer Simpson or Bugs Bunny, and some Pixar movies wouldn’t count if John Goodman or Craig T. Nelson character sounded like Donald Duck and Yosemite Sam. So this is mostly about fitting the voice acting to the style of the movie or the show and the characters in it, and perhaps admitting that what annoys you doesn’t annoy everybody else.

Right, it’s so sedate it’s almost radio. Maybe I’d like it better if I gave it another shot.

FYI, Hank Hill’s character is Mike Judge doing the voice of a redneck. The voice for him was originally developed for Anderson from Beavis and Butthead, Judge’s other creation.

For the most part, the characters on Futurama are played mostly straight. Zoidberg, one of the exceptions, is a creature of pure fiction (an alien) and would not sound “realistic.”

For other non-realistic voices, check out any sketch comedy show (MadTV, SNL, etc).