For rodents I would recommend guinea pigs and rabbits (not actually rodents, but whatever) over hamsters, hamsters can be neurotic, evil little creatures. (They also like to escape and terrorize their surroundings). A well socialized guinea pig can be fairly smart, and will be quite happy to see you and get snuggles, they have a surprising amount of personality. Ditto rabbits. Now there's a third option, but some people really hate them... rats are super smart, very clean and quite affectionate, some people have issues with the tails though, or just the concept of rats in general.
@Valdis, sounds like just what the doctor ordered.
@Merrick, really? I've never seen a snake do that before! I've always liked snakes but I tend to like the bigger species.
I'd love one of these little critters (San Francisco Garter Snake) but they're an endangered species.