Hm...to tell you the truth, I think I was too young back then to even understand what the 3DO was - I was 9 years old when the 3DO hit the German market in 1995 (kinda late, huh? Same year as Saturn and PSX, too), and back then, all I was interested in were the Super Nintendo and Game Boy. I still have to get a 3DO someday, but it's kinda difficult to get a console complete with its box and manual in Europe.
As for your list, you definitely got the obvious choices Wing Commander III and Super Street Fighter II, even though I think there might be a handful of other games worth mentioning.
What about FIFA International Soccer, for example? The 3DO version received rave reviews in Europe for being a revolutionary step up from the 16-bit FIFA games graphically and in terms of gameplay. Some even considered it to be the best soccer game of that time, together with International Superstar Soccer Deluxe, dethroning Sensible Soccer.
Super Wing Commander isn't too bad, either, judging from what I've heard at least.
Gex received critical praise at least from some magazines as well, and it sure looks like the best platformer on the system.
Let's not forget Samurai Showdown, which, supposedly, was more faithful to the arcade and NeoGeo versions than the SNES and Genesis ports.
Then there's Need for Speed, perhaps. Probably not so great anymore, but noteworthy as the granddaddy of the series.
As a more obscure choice, why not Daedalus Encounter? An interactive movie with surprisingly ambitious production values and starring Tia Carrere
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Well, maybe as some sort of gag, why not make a poll for the worst 3DO game after this one? There are quite some nice choices, after all: Mazer, Kingdom: The Far Reaches, Sewer Shark, Strahl, Way of the Warrior or Virtuoso...and tons of low quality interactive movies.