Stormlight has its hooks in me hard, which is a kind of torture given the pace of release. I just hope Sanderson and I both live to see it finished. Even if you weren't thrilled with Mistborn, the Wax & Wayne books take things in a decidedly different direction, and Bands of Mourning starts to get into broader Cosmere business to a greater extent than I think any of Sanderson's novels so far, though I haven't caught up on the Cosmere novellas.
I've enjoyed several reads/listens of Mistborn, but it has its flaws. Much of the second and third book was a slog the first time through, so heavy with exposition that he was literally prefacing chapters with encyclopedia entries, but the ending more than pays off IMO. Also, the slow part was more tolerable/rewarding on re-reading.
The Reckoners books are fun, if decidedly YA, but while they were coming out I couldn't help wishing he was working on literally anything else (but especially Stormlight). I wasn't thrilled with Steelheart, really liked Firefight, and haven't gotten to Calamity yet. Warbreaker was, IMO, not good, but Elantris, while having some of the same "early Sanderson" flaws as Warbreaker and Mistborn, was pretty cool.
New Stormlight is pretty much the only item on my "Must read immediately!" list. Anything else I leave to the vagaries of library holds, price drops, mood and chance, but when I know new Stormlight is coming, everything else gets put down
