I had a 3DO and Saturn back in the day. Nearly all the good 3DO games were on both the Saturn and the PS1. The only two good games I can think of which were "3DO Exclusives" were Slayer and Guardian War. That said, I think the 3DO versions of many of the multi-port games felt a little bit better playing on the 3DO. And it wasn't like I didn't enjoy my Saturn. I played A LOT of Panzer Dragoon Zwei. It's simply undeniable the Saturn has a much broader library.
My Saturn died. I gave my 3DO to a friend.
I've sometimes thought about getting a replacement Saturn. I've never carried through. Honestly, when I start really analyzing it, the Saturn doesn't have much which appeals to me outside of the moment of the 90s.
But I regret giving up my 3DO. I truly miss it. In fact, my original one from the 90s is still in service and is used regularly by my friend. He still regularly plays Slayer and Road Rash on it. Sometimes I'm reunited with it, and I race a Lamborghini Diablo down the city streets in Need for Speed just like the old days.
My answer is 3DO, not because of any objective measure, but because of subjective personal preference and nostalgic attachment.