I recommend hamsters: they are cute, they live for about 2 years, they're easy to take care of.
I would say just get one, however, because if you put more than one in a cage they might fight, especially if you have two men, and if you have one of each you will end up with a litter of about 10 hamster babies. If that happens, you very well may have the misfortune of witnessing the mother eating one of the babies, if one of them comes out runty or stillborn.
In January of 2005, I transported 11 hamsters, in a total of about 6 cages, from New York to a small town in the middle of the country, inside the cab of a U-Haul truck. Before I even left the city, an argument erupted in one of the cages, and two hamsters came to blows. I foolishly reached my hand into the cage to separate them, and the larger of the two -- his name was Xerxes or something like that -- sank his teeth into the tip of my pinky finger, and when I yanked my hand back, he didn't let go, he was dangling from my hand. I still have two tiny scars from the assault from where his top and bottom teeth were. He was strong, like a solid chunk of muscle the size of a knish, and his coat was of a coarse, black and gray hair.