Seconded; I had a pair of rats until recently, and they made awesome pets: affectionate, smart enough to play with, and with distinct personalities while being pretty low maintenance (and willing to eat most of our food scraps). If my partner hadn't developed a skin allergy to them (which made handling them suck for her) we would for sure have acquired more when ours died.

Edit: in retrospect, I'm pretty sure that quote is from the breeder we used! She's doing hamsters and rabbits now as well.