The April 10th installments of these series (Terminator's was the season finale) both delivered satisfying complexity. Terminator has gotten more interesting than the movies were--and I liked T1 & T2 a lot. Dollhouse is finally achieving what Whedon and Dushku both promised in interviews: that from the 6th episode on things would get interesting. They have, and it is. In both series we're getting fascinating plot arcs.
This means new viewers are going to get lost. So get the first seasons of both on DVD and watch them before tackling what's going on now. It'll be worth your while.