Get a rat if you want something in the rodent family, Rats are very intelligent and you can teach them many things. I had 3 Rats and they loved to play in their cages which I had all kinds of cool stuff for them. I also was able to teach them how to use a litter box (meant for a rabbit but they used it).
Hamsters are shy, if they get out of their cage, You will probably never see them again. My rats (Believe it or not) I actually trained to come to me when they heard a "chichichich" type sound, so if they were wondering around the living room or the foyer they would come strait to me.
Anyway, If you do get a rat, I suggest getting them from a local breeder, Because pet shops they carry a sickness called
Mycoplasma and it will decrease their live span. I learned that the hard way, I actually bought my rats to the vet multiple times because we loved them so much, So they lived for a nice 4 Years(Average livespan is 2-3years). But even then, We spent about $200-300 in medicine over the last 2 years of their life, So I suggest finding a good well known local breeder if you are going to get one. \
Anyway, Hoped this helped you.