I mean expensive-but-you’ll-actually-let-other-people-touch type interactive things. Indoors. Fun stuff. A craps table? A blackjack table? Or a full size pinball machine? A two or three lane bowling alley? Setup for a small band?
How about a few full-size arcade games? I remember the ones (late 80s, early 90s) where you could select 3 or 4 different games in one machine.
For my math-&-physics side, I might go with a pool table (to learn trick shots) and a full-size roulette wheel.
Nostalgia? For me, maybe a few “old school” consoles, so I could play the likes of Joust 2, Tempest, & Ms. Pac Man.