Too many to choose from, but solo hike in Gates of the Arctic NP, Alaska, might take the cake. Three Passes trek in Nepal, Wakhan corridor in Afghanistan and Fann mountains in Tajikistan are also top tier. Also did some really nice hikes in the Carpathians and the Pyrenees.
>>2098786Very much enjoyed the sections I did, being Wadi Rum to Humeima and Petra-Dana, still miffed I had to cut the first leg short due to a a broken rib.