Whichever one didn't piss you off most recently.
In my experience, no matter how much I like a pack for multi-day ski trips initially, eventually I will hate it. Is it big enough to hold everything you might want? Then it's too big to ski well. Is it small enough to ski well? Then it will be annoying packing or unpacking it. It will probably even explode somewhere when you overstuff it for the umpteenth time.
I usually like them best after one or two trips. So a pack that's been tested by only one or two trips. The Wild Things Ice Sac was probably my most enduring favorite for a few years there.