I have 3 cats and 4 dogs, and all are quirky in their own ways.
Samuel Adams (cat) is the only cat I've had that knows his name. I also taught him as a kitten to sit on his back legs and put his paws on my hand for a treat.

This backfired because when I am eating he climbs all over me and paws at the food. He is also not picky and will eat carrots, broccoli, green beans, etc.
Jack Daniels (cat) will be walking along and randomly dash from 0 to 60 and leap up the wall. He also likes to eat broom bristles. He has also learned to bully the dogs, and then seems confused when they jump out of their skin to get away when he is trying to rub his head on them and be affectionate.
Shooter is the weirdest of the cats. He also loves water, when I flush he will come running to watch the water swirl and go down the drain.

I don't even have a lot of examples for him, because everything he does is just goofy. He was a sickly feral kitten that I caught when the dog cornered him in the yard and I think that has something to do with it.
Mollie (beagle) does the butt rubbing thing someone else mentioned. She likes when I'm in my recliner because the foot rest is just above her back so she can scootch up to it. She will also back up while growling if another dog is in a crate or on her bed and she thinks they might challenge her if they're face to face. Passive aggressiveness at it's best.
Brenna (German Shepherd) looooves romaine lettuce. She likes to drink water while standing in it, so if there is a dirty mud puddle she will drink that instead of out of a clean bowl because she can stand in the water.
Spot (pointer) doesn't really have any quirks. She is my least favorite dog, I kind of got stuck with her to be honest. lol Inside the house she is very sweet and loves her Mr. Bill toy (if I say "oh noooo" like the toy or ask for Mr Bill she will usually go find him). Outside she is destructive and obsessive over any rabbits/moles/etc. living anywhere in or around my yard.
Fezzik loves empty water bottles (perrier bottles are his favorite) he will chew the cap off and walk around chewing the cap like gum. It used to scare me but he never swallows them, eventually he gets bored and spits it out. He is about 70+ lb and fancies himself a lap dog, he loves getting up in my recliner with me.
