Dressler and Chemerinsky both have "Understanding"-type books that explain their casebooks.
Not all the E&Es are great. The Torts & Civ Pro ones were so good, I just got in the habit of buying them for every class. But Contracts was either not good or not suited to the way my prof taught, and every time I try to read the Con Law one my eyelids get heavy. Property's ok, but I don't think the examples are very good.I think finding a good supplement is part trial & error.But a good site is lawbooksforless.com. If you spend more than like $60 or so they'll FedEx everything to you for free.