The indonesian one with blue lava is among the weirdest volcanos in the word. Alongside Thrihnukagigur in Iceland (the only volcano where you can safely enter in it's magma chamber) and the Mount Etna (that is both a shield volcano and a stratovolcano). I would also take in account the over 80 volcanos of the Chain des Puys. They are all dormant but they're beautiful, all covered in green even inside the calderas.