In Uzbekistan there are no "luxury hotels" esp. outside Tashkent (which is surprisingly pleasant, and the metro is an absolute must-see). In Nukus, Jipek Joli is really the only choice. In Samarkand and Bokhara, the most interesting places to stay will be guesthouses, though there are somewhat staid looking hotels where tour groups stay. The Amelia in Bokhara is very charming (and cheap), as is the Amulet.