The benefits of starting somewhere else:

ELANTRIS is a stand alone novel
MISTBORN is a completed trilogy
Warbreaker is a stand alone novel

To date, I would say that MISTBORN is one of the best trilogies of the last 20 years. By the final book, Sanderson has hit full stride as an author... and the series features one of the very best magic systems ever.

WARBREAKER is a fun, somewhat complex novel, that involves a lot of humor and interesting characters.

Elantris, his debut, probably is the highest concept, but it suffers some first novel weaknesses.

Of course, you can read THE WAY OF KINGS, my favorite book of his so far, and then read others while you are waiting for the next one.