I'll bite.
I was a vet tech for many years, and I grew up with LOADS of pets, both domestic and exotic, large and small.
We have had:
fish (bettas, tropicals, and koi)
cats (we're on our fifth cat in my DD's lifetime-- though she has sensitized to them, it's taken almost 16 years, so not bad)
dogs (the third dog kind of pushed DD over the edge of the atopic bandwagon, I think-- she's now allergic to THEM, as well)
budgies (parakeets-- we had three, but the cat + budgie thing was a bit more than we bargained for, let's just say, so we gave them to another relative)
insects
alpacas (yes, really)
rabbits (DD and I are now both highly allergic-- sensing a trend, here, are we?)
pigeons
fancy bantam chickens
As a child, I had at various times-- a ferret, a pair of rescued squirrels, guinea pigs (cavies), gerbils, hamsters, dogs, cats, parrots, a chinchilla, cockatiels, rats, and my father once rescued... um... a barn owl. This doesn't include the pigs, horses, ponies, cows, and random other livestock like sheep and chickens and goats...
I'm too highly sensitized to rodents now (occupational exposure) to ever have one in my home again, unfortunately-- rats ARE great pets. Just as well, though, given DD's rate of sensitization. Rodents are the world's WORST idea for anyone with allergic tendencies, though, I'll say that.
I would definitely look at a budgie. They are a pretty easy pet-- and they are a very good companion, in that they like being "with" their human families in the same basic way that a dog does. Ours used to enjoy chatting with me while I cooked in our kitchen, which adjoined the room where they were caged. I recall my cockatiels having the same gregarious and pleasant nature about human interaction.
The one problem with fish, insects, or reptiles is that they are not really interactive in quite the same way that a warm and snuggly kind of pet is. Some songbirds (finches, canaries) are this way, too.
