Well, hm. I am biased by games I've played or am playing, and group dynamics.
In general, I would like a game where the GM and players alike are on the same page regarding group and personal goals. I've been in a few groups that work well in that regard, but more where things just don't line up. I think this matters far more than the system.
But as for system, I'd like one that doesn't devote all its detail to round-by-round combat and huge catalogs of spells and powers oriented to round-by-round combat (or to short-circuiting narrative), one that allows for ways to resolve combat at a higher level. Blades in the Dark is a pretty decent stab at it. It sometimes takes work to make certain things not just a dice roll against a clock. But that's no worse than whittling down hit points round by round! Blades is also not great for really long-term campaigns.
I know very little about Genesys. Is that the one with the funky dice?
I have normally been a player, but am about to take my first real stab at GMing since high school, for my Torg Eternity group, with action centered in the cosm of gothic horror. In Torg, the system and premise kind of actively undermine gothic horror, and the way it handles gothic horror actively undermines the premises of, well, everything, including the gothic horror! I am wracking my brain to homebrew some stuff that will actually provide a sense of dread, rather than of merely losing points in stats. There are other problems with Torg horror I won't go into.
Given all that, I guess right now I'd like a system that can really handle gothic horror well, in a setting that establishes premises for stories without pre-scripting them, a focus on narrative vs. task resolution, and a group that can be above-board about motivations, in general alignment but with enough latitude for interpersonal conflict that doesn't wreck an 18-month series of sessions.