I have cats. I have dogs. I have a ferret, and I had a bearded dragon. I love them all! I couldn't possibly pick just one, because they all have their pros and cons. My cats are a major pain in the ass when I'm cooking. My dogs annoy me when it's the middle of the night and someone walks past my house and they feel the need to bark as if we're about to have a swarm of criminals invade the house. My ferret isn't very affectionate, but she will, when she's in the mood, snuggle and fall asleep on you (More so now that it's starting to get cold and she's not used to the lower temperatures.) My bearded dragon was just awesome all around, but he wasn't the type of pet you could really cuddle with.
If I had to pick one, I just couldn't do it. I'm the type of person who loves animals a thousand times more than most people (My kids and husband are the only exceptions to that rule.). I'd own a zoo if I could, but my husband wouldn't let me. :(