I had really wanted to get Assault on Hoth, and had such high hopes for it, but it's just too disappointing, especially at its price-point. The Ewok Village was a worthy substitute, especially after watching a couple Youtube reviews. It'll also pair nicely with The Battle of Endor, and maybe an AT-AT and Imperial Shuttle.
But my favorite UCS set (of the ones I own: Death Star, Imperial Shuttle, B-Wing, Sandcrawler, Ewok Village) is still the Death Star. It displays well, recreates most all the iconic scenes, and has excellent playability. I don't know how LEGO will be able to top this one, but I look forward to seeing what they come up with. Now granted, I have yet to actually
build any of the other sets, but I'm pretty confident the space station won't be dethroned. =)
I really hope (more like a pipe dream) they get around to releasing another UCS Tantive IV, as I didn't return to LEGO until well after the first release. It's too expensive on the secondary market, and it has room for improvement. But the standard model remains a personal favorite.