Sig for me, Glock places a close second though. Both have the availability of good high capacity factory magazines, though admittedly the Glock holds the edge there, the kicker for the Sig for me is its trigger. Both have the ability to become Lego projects and that’s just with factory parts, never mind the plethora of aftermarket goodies available for both. Caliber conversions, more available selection for holsters, they both have it all....
Perhaps the kicker for me aside from the Sig’s trigger is that I have some Glocks, I presently don’t have a Sig