He's the guy they brought in to finish the robert jordan series isn't he?
I almost picked him up last week as I need something to keep me busy until RR cranks out the next GoT and Rothfuss finishes his series. I went with Joe Abercrombie and S.V. (?) Parker instead. If I did pick him up which series is the best?
He did finish Wheel of Time, yes.
Many of his series is set within the same universe, but all of them is written to stand alone. His best, in my opinion, is The Stormlight Archive starting with The Way of Kings, but Mistborn might be a better starter for his work. Of course, Warbreaker is a free online novel, so that'll be easiest for if you want to save money.