SteelSeries (the bigger the better) soft pad. I've been using them for about 10 years now. They're by far the best pads I've ever used. Hard mouse pads (at least the ones I've used, Razer's, Logitech's, multiple glass pads) tend to have almost no resistance and I hate that.
I switched to a hard mouse pad about 5 years ago and am finding they actually last longer than any of the soft ones I have ever had. I only bought 2 hard mouse pads in my life and they are both used to this day.
Every soft pad I've used started to peel away from the rubber mat and cleaning it just made it worst. It seems more likely the mouse will break down before the mouse feet ever get worn out from a hard pad for me so far.