Moonmadness, Snow Goose and Mirage are definitely amongst my favorite albums, but the debut is magical aswell. ¶ I also recommend the songs "Echoes" and "The Sleeper" from the Breathless album, or if you're into atmospheric guitar tracks like Marooned by Pink Floyd, you might wanna check out the title track from Stationary Traveller and "Ice" from the I Can See Your House From Here album. If you're into more "pop" style songs, you can try "You Are The One" from their 80's album The Single Factor and "West Berlin" off of Stationary Traveller.
Low fanbase? 320 000 scrobblers is well above average for this site, be it prog rock or bands in general. They may not be as popular as Yes or King Crimson but they aren't as obscure as Nektar or Anekdoten or Anglagard.