Va and negative g's & fun non-acrobatic maneuvers

Seriously, if someone has something to suggest that's fun and safe,
within normal operating range and category, please suggest. It's a
buddy's bday soon and he wants to go up. Again, I am not looking for
doing anything aerobatic.

From level flight at slow-normal cruise, with plenty of altitude to
spare (i.e 5000 AGL), pull the power back to idle and bank the thing
over to almost 60 degrees letting the nose fall over in a slow steep
banked 180 degree turn. Watch your airspeed and make sure it stays at
or below Va. Level out and then do it again in the opposite bank, to
make a big falling slow figure-8 pattern as you descend. Keep your
bank at or below 60 degrees and the nose down angle less than 30
degrees and you're still legal. Because you're not maintaining level
flight in the 60 deg banks, you're not really pulling any Gs in the
banks either. The most Gs you pull is when you level out after you're
done with the steep banks. Maybe 1.5 Gs at the most if you're sloppy
about it. One of my favorite "fun" things since you get a windshield
full of straight-down plus a wee bit of almost-zero-G feeling without
hardly any stress on the aircraft at all.