Sakura of DOOM

Cats, I think, are very easy, but maybe I've always been lucky with the ones I've had. My current cat is more demanding attention-wise and she's been a bit more of a pain than I'm used to, but I think boy cats are more laidback than girls, and older ones especially so. You can even go away for up to two nights and leave them well-stocked with a food bowl, water, and a litterbox and they'll do fine, which is my personal definition of low maintenance -- plus scooping out a litterbox is way less annoying than cleaning a rodent cage. No bathing, no walking, etc. It's also easy to get someone to cat-sit by checking in every day or so when you're out of town, versus taking the animals to their house.

I would basically go down to the shelter and tell them what you're looking for, and I'm sure they'd easily find you an older, chill boy cat who's litter-trained, fixed, has all his shots, and will cuddle nicely with you without being too demanding.