Hello, I am a recurrent LEGO buyer but there are still a few sets I have yet to see (either from themes like Star Wars or general LEGO). The sets I would love to see are:
Episode 3 Crab Droids (six legged droids with weapons on the underside with the tip of the legs with claw like attachments to scale difficult terrain but it has been proven effective at close range combat againts the GAR (Grand Army of the Republic) troopers;
Clone Wars Umbaran Ballon like ships (these are seen in the Darkness on Umbara arc hovering in space with an oval shape);
Star Wars Deth Troopers (think zombies in Star Wars part of the same named novel that is very clearly for an adult audience, but the zombies themselves shouldn't necessarily be restricted because of it, after all LEGO has made multiple of the living death in various themes (including Legends of Chima).