It could be because she’s wonderful, or awful. I’m flexible. 
(So flexible, in fact, that I’m punting this question to the fans, since it didn’t get answered during the Q&A. 
)
I choose Paula’s mom from The Violent Years. I think Ed gave her a raw deal, frankly.
I also really like George’s foster Mom from The Magic Sword. She did a whole lot of the work just so he could marry into royalty.
The mom from Mac & Me seemed like a pretty nice lady
I think Jimmy’s mom from I Accuse My Parents. A real party gal.
Gumby’s mom.
…because there’s just something about a woman serving crackers and milk with a sweater wrapped around her head? 
Um, yeah I guess?
As was Florence Shelby in Avalanche.
Tony’s mother from Zombie Nightmare, because she instantly went all-in with the whole “please bring my son back as a zombie to violently avenge his own death” thing.
She wasn’t seen much, but Chase’s mom from “Giant Gila Monster” seemed like a nice lady.
I was coming here to say this. I sorta wish there was a scene of her enjoying her sweet zombie revenge. Probably the best mom in the series…well, except for Crow’s Harlow-style “mother”.
Bob & Judy’s mom in Young Man’s Fancy created a conspiracy for her daughter’s love life that rivals the Kennedy Assassination for its intricacy and effectiveness, which seems to be her thing as it’s implied she did similar to win over their father. I’d say that makes her the best mom since Angela Lansbury in The Manchurian Candidate!
The potato mom in Deathstalker for taking a stand against junk food!
FIFY
Either that or they like…those…very squared. 
Can I count the mom from Birdemic? She gets a bad rap for her weight: she’s a caring mother who takes a genuine interest in her daughter’s life. And she didn’t laugh when her daughter brought home… Rod. That is love, ladies and gentlemen!
Hello!
Thank you!
Hello!
OK, that made me laugh for reals.
Hmm, can we count this lady as a mom, even if she became one by convoluted means?
