Speaking of Sanderson. I loved Mistborn the first time I read it. It was one of the first modern fantasy books I'd read at the time mostly being a science fiction aficionado. I was super attracted to something that wasn't elves, dwarves, and generic wizards.
Fast forward a few dozen more series and a few years later I re-read it, and was thoroughly unimpressed. Tired character tropes, overwrought magic system, unrealistic interrelations, and little substance beneath the glitter. Don't get me wrong, it's not a bad series, just not the revelation I felt like it was the first time around.
Malazan on the other hand, I don't think I'll ever tire of re-reading. Though, I haven't really gotten much into the books outside of the main, ten-book series.