I'd go with Hobb for depth. The Farseer, Tawny man, and Liveship trilogies all have very rich and full description and world building. Hobb also tells a story very well, but takes her time.
Sanderson also doesn't rush, and in my experience (so far) his work is very good in terms of entertainment (nice dialogue, a "light touch", some humour), but it feels less "deep". Sometimes I like reading something that's just easy and fun, and Mistborn is very good for that.
I haven't read Stormlight yet, but I'm expecting it to be at least as good as Mistborn, and what I've heard suggests that it's better.
Coragem
I quite enjoyed the first in the Stormlight Archive, The Way of Kings. Great story, a lot of hidden depth to the plot (important for the first novel of ten), and good, discernible and distinguished characters. Lots of hinted back story, but not as "chuck you into the middle of the Atlantic" as Erikson's Malazan Book of the Fallen. Sanderson's magnum opus (at least so far, until he starts another one) is looking pretty good, and deeper than his earlier stuff.