I've had fish, hamsters, cats, a bunny, and a dog.
I have to say that my dog has been hands down the best. I've never seen a dog so happy to see its owners return from being gone, even if I was only gone for five minutes, and he has such a fab and cute personality. Even being nine years old, he still acts like a little puppy. They're high maintenance, but so are fish tanks and I'd much rather have a dog than a fish tank.
My hamsters actually had interesting personalities. I know people will probably say oh hamsters don't have personalities, but I think one of mine was an escape artist. It bit through every cage it ever had, and twice I caught it in my bed while I was sleeping after it had opened the latch of its cage haha. They were really cute, I was gutted when they died
. For being so small they were actually quite high maintenance. They'd always make big messes around their cage and their sawdust had to be cleaned out constantly.
I only had the bunny for a few months, and it was a long time ago so I don't really remember, I just know it hopped around chewing wires. It was really cute, I wouldn't mind a bunny. My friend has a chinchilla and those seem really cute too.
Cats are pretty cool, I just wish they were more loving. My one cat will act nice for about five seconds and then bite you a billion times, and my other one doesn't bite but it jumps up walls and races back and forth from one end of the house to the other. I think it has a psychological issue, but it's still funny. Cats aren't really high maintenance either.
Birds and fish are well.. Sort of boring.