One thing I always wanted to try...sailing. OK, what is better FLYING or SAILING...I know hard to compare...but both need skill and precision to do correctly...which gives more???gratification (not really sure what I was going for lol). Sense of accomplishment 
Sailing is pretty easy to simply get the boat to move. An old saying is anyone can get the boat to move, it takes a sailor to stop one. Sailing is very technical and takes a lot of effort, skill, knowledge and experience to do well. I was a noob even though we had been doing it for 9 years. I had improved a lot but still had a loooong way to go.
My wife and I loved having the airplane. It was our escape machine and there is no better place to escape than the wilds of Alaska. Flying here is more relaxed than most of the lower 48 -- less airspace restriction and with the right airplane you can land almost anywhere. Even in our 182 with minimal mods we were able to get into less than 500' gravel strips, river sand bars, etc. We many times would go to our favorite chicken place and grab a bucket then fly to a remote strip (named Bold
located at the head of a lake and just below a glacier to enjoy our picnic surrounded by stunning views.
After selling the airplane and returning from the bombers we bought our first sailboat. It became our escape machine. The Kenai Fjords National Park and Prince William Sound became our sailing grounds. We'd get out a day or so from Seward, far enough the weekenders would be around, and virtually have the ocean to ourselves.
As to which gives the most gratification I have to say they both do equally.
Here's some sailing images:
https://www.dalefalk.com/Boats
