A little late to the 32X party here, but I managed to get a full set back in the day and other than Spider-Man it was a pretty cheap set to collect. I think the library is a little underrated - it's very small, yes, but many of the games are exclusives, and many of the ports are actually very well done.
Space Harrier on the 32X is still my favorite port of the game, it is near arcade perfect, and while it doesn't have the customizations and extras of the Sega Ages version on the Saturn, the control feels the best on the Genesis pad. The Virtua Racing port is also the best - much cleaner than the Genesis version and more faithful to the arcade (and just better designed) than that disappointing Time Warner port to the Saturn. Virtua Fighter is a cleaner, better port than the Saturn version (done by Yu Suzuki himself), although the music isn't as good (naturally) but the added camera angles are fun. After Burner is similarly solid, although I prefer the Sega Ages version with the Mission Stick and the added menu options and soundtrack. Then of course there's Star Wars Arcade, which is solid and the only home port of that iconic arcade game. T-MEK is also exclusively ported to the 32X and not a bad game either.
When it comes to originals, you get unique entries into classic SEGA IP's like Zaxxon's Motherbase 2000 and Knuckles' Chaotix, and then unique games like the Hummingbird shooter Kolibri (from the Ecco team), Tempo (a fun platformer from Red Entertainment team behind the Bonk and Gate/Lords of Thunder games), Metal Head (a decent mech game with great texture-mapped graphics), Shadow Squadron (a spiritual sequel to Star Wars Arcade) and a guilty pleasure of mine, Cosmic Carnage, which is an excessively bloody and disgusting Mortal Kombat clone with a space slant.
Many of the ports that would hit other non-SEGA consoles are also of high quality - the general consensus is that Blackthorne, Brutal: Paws of Fury, Star Trek: Starfleet Academy, Pitfall: The Mayan Adventure, and Primal Rage are best on the 32X, and Mortal Kombat II and NBA Jam TE are both quality ports themselves.
Really, the only disappointment on the system is Doom, which severely under-utilizes the system in what's commonly been called a rushed port. BC Racers isn't as good as the SEGA CD version, but still an enjoyable game. The Spider-Man game is pretty dog shit and was also rushed, so naturally it's the most expensive game on the system.
And that's basically the system in a nutshell outside of a bunch of Digital Pictures CD games and a bunch of sports titles. None of the games are classics, really, but a lot of them are interesting, unique to the system, and pretty enjoyable. It's a fun system to fire up from time to time and I definitely recommend tracking one down provided the prices aren't too crazy (I've been out of the 32X game too long to know). Personally, I play Virtua Racing, Space Harrier, Kolibri and Cosmic Carnage the most.
