here you have a bunch of one and two tube radios.
http://makearadio.com/tube/index.php
one of my favourites is the 1T4 (DF91) shortwave set,
http://makearadio.com/tube/sw1.php
6K7 one tuber is another
http://makearadio.com/tube/6k7-dx-radio.php
he also has a one tube superhet (ok he uses a germanium diode detector but...)
http://makearadio.com/tube/6ba7-superhet.php