I would go with a beta, all of mine have lived almost 2 years and have survived a couple moves. My last one was murdered and eaten by my cat so we no longer have fish.
Only one fish per bowl though since betas kill other betas (and other fish)
They sell little cheap cute tanks for like $15 at walmart for a single goldfish. I wouldn't have a gold fish without some type of filter, or pump moving the water around. As mumita said they are filthy! A beta is good because you can even put them in a vase with a live plant and it will be fine. The also sell beta tanks for a cheap price! I love fish!!!
I have had fish for 10 years now, and about 6 years ago I branched out to Salt Water. . . .DH loves the tank, but hates cleaning it with me being pregnant!
A Beta Fish, the ones that you can put in a glass and they swim around in circles. They don't require anything but food every once in a while. But they can only live alone cause they'll fight with others. I had a Beta for years. I changed the water every few weeks and thats it.
Goldfish ARE very dirty I used to have them and the filter would get absolutely disgusting in 1 week! they are very high maintenance. They also poop A LOT and they eat everything in sight.