The rescue in ROTJ has always been incredible unbelievable and made no sense at all. The Jabba palace bit of the movie is probably one of the worst bits of the OT IMHO. But the Rancor battle, the scene with Luke slashing up everyone on the barge, the original sarlacc, and Leia choking Jabba to Death in her metal bikini all make up for it... mostly.
Though I must say, there is nothing in the entirety of ROTJ that makes it worth sitting through Jedi Rocks for, NOTHING!