I did my 20. All in all, most days I loved it, some days I dreaded it. But it was never dull. Nothing I ever did or ever will do can match the mental rigors and excitement of being the Officer of the Deck on an Aircraft Carrier during flight operations, with shifting winds, and merchant vessels and fishing boats all around you.
Every service has its purpose. The Navy is the one you want for Strategic Sealift, Nuclear deterrence, and Strike warfare. It's been said, of the last 80 or so incidents where the U.S. Government required military intervention, the Navy was the first one called in about 65 of them.