Rats look like those weird water pig things. Mice are cute and fuzzy. Male rat can be the size of a small cat, my biggest mouse weighs 48g. I don't like rats, they give me cold shivers... If a mouse bites you it hurts but that's pretty much it, if a rat bites... ick.
I basically never cared much for rodents, I got the first two mice out of a crazy, spontaneous idea

I guess gerbils are okay too, but mice are probably easier to tame and they are more adaptable. Besides, they have a great number of variation in colour and marking and type of coat. I'm trying to breed long haired ba&ar&ag&cc/br