That's a good question. For me, I think I'd want more PC releases added on gamepass. I get Gamepass ultimate whenever I do subscribe, and I've been trying to find more games for PC.
I'd like to see that new Sonic Frontiers or whatever it's called added to gamepass, mainly because I do want to play it, but don't want to spend any money on it. Aside from gamepass of course. Other than that, The Callisto Protocol (I hear it's tough), and that Ready or Not game, though I don't think it's out on Xbox gamepass, just PC right now. Other than that, I think Stray would be cool, but I don't think it's coming out for Xbox.
It's hard to say too, because so many games are releasing on gamepass now. Exclusives already release day one, so that's awesome in itself. But even some third party devs are releasing through gamepass day one, and I really love that.