OR is very narrow in scope. Unless you go advanced practice, you'll probably only be a circulator. You work closely with the docs in some ways, but you won't learn much about disease management.
In ICU you are more indepedent, work closely with docs on a variety of patients, and learn more long-term management.You learn a lot more critical thinking (in my opinion), and learn more of what you need to move out of bedside care into a more independent role. Surgery, like OB tends to limit options if/when you get sick of it. If you want broad experience, go to a MICU or SICU. A SICU (surgical ICU) could be a good option for you if you're interested in surgery. Unless you want do surgery forever, I would not start there.
I guess I should disclose that I work in a CCU/MICU. So I'm a little biased :)