Well, it depends on what you're interested in and the type of environment you'd like to live in.
Some of this has been already mentioned, like that Iowa has better rankings overall. I'd say if you're interested in creative things or the humanities or even like pre-med or pre-law, Iowa's better. If you are more interested in something like engineering or agriculture sciences or fashion, then Iowa State is better. As far as the towns, Iowa City seems to have a more vibrant culture. Especially if you're interested in a party scene at all, Iowa is the way to go since they're often ranked pretty high as a party school. Ames seems a little less exciting in my opinion, but depending on what you're looking for, maybe that's a good thing.