Both!
Seriously, that would be a difficult choice. The rosy you can take out & hold while you watch TV or type on the computer. They explore a bit but for the most part tend to stay put, so you don't have to devote a lot of attention to it. The corns usually explore way more when they are out so you have to pay a bit more attention to them while handling them. But that also makes them more interactive & satisfying to some people. I would suggest, if you can, handling both species before buying one so you can get a feel for their differences & a better idea of what you'd like more.