Agree with ER, derm, ICU, ortho, and rads. These are things that are hard to learn on your own. You'll get plenty of Psych and Endo, so I would bump that further down.
One not mentioned is OB, which I would highly recommend. Being comfortable and confident on L&D will help you tremendously when you are an intern/resident, especially if your rotations are opposed. OB is one where if you demonstrate capability early, you will garner people's respect, and hit your numbers early (ICU is the other one that I highly recommend).
As far as the fun ones that you may not have a chance to do again, I recommend re-doing Gross Anatomy, as a TA doing the prosection. With the clinical experience, it's nice to go back to the basic science, and it'll help you (re-)learn MSK. I would place this experience in front of ortho, personally, if you had a choice; or ask if you can combine anatomy with ortho clinic as an independent study/self-designed rotation.