This was a hard question for me! Each of them have meant so much, but I posed the question so it came down to a tie. One dog, one cat.
I'll start with the cat. Yahtzee was a six toed cat, that got his name because of his habit as a kitten of sleeping in my kid's Yahtzee game box. He was a least 17 pounds of long haired, blue eyed cat. One of the funniest animals that has ever been a part of my life. He would sleep in the bathroom sink, and never did he move when you turned the faucet on to wash your hands. As he got bigger he sorta oozed over the sink! He would go right up to one of the dogs and swat them in the muzzle with his over sized paw, just for the heck of it. My kids would put him in a plastic grocery bag, and take him around the house. There he was with the bag really sagging and he just hung his head out, he actually seemed to enjoy it. He was so full of personality.
My favorite dog was Skirt, a smaller dog then the rest of the pack. She came onto the property one day and never left. I don't know where she came from or how old she was, but I do know there was more personality packed into that little girl then most dogs have.
At night she would sleep between Mr. P and I, and I remember rolling over and becoming face to face with a dog who was laying on her back with her head toward me, softly snoring. A favorite memory of mine!
Those are my two favorites, who are yours?