Depends on your definition of fun

I can do two things which can be "fun" I guess. One is what is called a "G drop"...basically you suddenly lose altitude and for about a second or so you and anything in the airplane is 'floating'. An instructor put a pen on the dashboard and did a G drop once and it was suspended in the air and it gives you a funny feeling in the tummy...kinda like when you're going downhill on a roller coaster.
The other 'fun' thing is a stall recovery. You pull the yoke (steering if you will) as far back as possible to the point where the wings stall (lose lift) and the airplane begins to drop which you recover from unless you want to keep descending uncontrollable and die of course