In general, Coach House is known as the top dog because of their one piece fiberglass shell... but one does pay through the nose for it. Other brands which make good "C"s are Lazy Daze, Nexus RV, Phoenix Cruiser, and Winnebago.
Forest River "C"s are a decent cross between price and quality. JMHO, they may have some rough edges, but that isn't too hard to deal with.
I generally demand a "C" has a fiberglass roof that goes over the sides (so water blown in a seam isn't an instant leak), a fiberglass nose cap, and a fiberglass cap at the rear. A rubber roof and seams at the edges is just an expiration date stamped on the rig due to water intrusion and wood rot.