Here is the place for athletes who like to run. I've been in 6 road races, the longest of which was 5 miles. It feels great after you stop, doesn't it?
Running is fun if you have company. Running alone kinda feels pointless. I do it sometimes for the exercise. I don't know about after you stop, but feeling like you can go forever is cool.
I have done 3 marathons, one was 30 miles, another was 15 miles, and the other one the 50 miles. The 50 mile marathon you could walk, so I ran 10 miles, walked 5 miles, etc...