3DO probably has the best version of Night Trap. Personally I don't care for the game [despite it's vampiric overtones]. I have it for SegaCD and 32X, and never play it.
I like old school fighting games so Samurai Shodown and Super Street Fighter 2 Turbo are great. Way Of The Warrior is cool too despite the bad reviews. WotW is very very cheesy, but if you're into making fun of freaks with mullets it's too much fun. I also prefer the 3DO version of Primal Rage over the other revs [not a great game though]
Gex is pretty cool if you like side scrollers. There's a lot of other cool games like Bust-A-Move, Blade Force, Return Fire, Road Rash, and the Shockwave series.
If you like older games with a touch of obscurity... the 3DO is a great system to have in your collection.
I got a 3DO and was pretty disappointed by the games available for it. However, it has the probably best version of Another World (Out Of This World). It's the only version with enhanced backgrounds, all other version use the same 32 color backgrounds, the 3DO ones has 256 colors. The sound has also been enhanced, well, the few sound there is. Looking at games like Alone In The Dark, Creature Shock or Lost Files Of Sherlock Holmes you're better off with the PC. Amazing, how that reminds one of the current X-Box situation
Jurasic Park Interactive has some nice grafics for the 3DO, and is supposed to be quite good. If you like RPG's, try to get a copy of Luccian's Quest, I can't find one anywhere, but its pretty much the only rpg for the system, and is supposed to be pretty good at that. I only have 2 3DO games right now, and neather is good, so I can't say any deffinet must buys from experience, but those are the games I would most like to get.
Shockwave is tight, ICE's voice sounded pretty hot the first time I played it, but now, that i've had some, it really doesn't do much, still it's a good game, funny parts, aliens carts suck up people and put them to work, hehe.
And Shockwave Jumpgate (the expansion) was too friggin' hard. but it's good if you want to complete the story.
Another one of my favorites is Twisted the Game Show, a tv show, i forgot how many players it was...
um... I have Super Wing Commander, and it's quite fun, especially with the touch of death, hehe, No FMV though just a picture with moving lips, sort of like when Conan does those interviews with Bill Clinton, hehe
Guardian War is a game like Shining Force, not as good, as there are only a few characters, not much magic, I really loved the boss music, just some raging guitar....
Hmm, alot of people liked Monster Manor, a FPS, just shooting ghosts and stuff, i didn't like it though... i think it got too hard.
The Lost Files of Sherlock Holmes rocked, especially bothering to the brusied rugby player, "Go Talk TO THE HOACH"
If you want a sports game, GET FIFA SOCCER!, and use the big ball mode, and hot potato mode, lol I remember the players just collapsing when it went off, HAHA later I'll connect the 3DO to my PC and get some pics...