Jabba's Sail Barge is the obvious choice for me, we haven't exactly been blessed with many Jabba playsets (except the cardboard throne room), and the whole Jabba scene is one of the coolest things about the Starwars universe.
The release of the SailBarge would also(hopefully) pave the way for more henchmen, skiff guards, bounty hunters as wellll as some new sculpts of the heroic characters ie;C-3PO with green glooop and dangling eye, bartender R2-D2, battle damage Chewbacca(ok so we don't really need him...) plus the long awited Jedi Luke resculpt.
Hey! We might actually get a Jabba the Hutt circa ROTJ!
But seriously, regardless of price, this would be the ultimate playset depicting one of the coolest batttles featuring the raddest aliens. Bossk could actually join in the battle this time!
Add to him Ephant Mon,ROTJ Boba Fett,new release Klaatu, the human guards(fluffy earmuff grey man,black cloth on face skiff man) Viggriev(Elom),Hermi Odle,Ishi Tib,J'Quille,Doallyn, half a dozen weequay and nikto guards, plus all the other scum and I'm in heaven!!