Add a few more interesting ATC callsigns I have heard

Angel Flight - group of flights helps with medical evacuation

Speedbird - British Airways, the one sometimes operates slower than birds in my experience

Santa - cargo planes in and out during Christmas time, a pretty cool name :)

In the good old days, many airplanes had an audio channel allowed passengers to hear the radio communication between ATC and the aircraft, callsigns were no stranger if you listened carefully.  It's also quite fun to learn their phraseology.  I recall I heard a few times the pilot said "wilco" or something similar over the radio, later I finally found out that "wilco" stood for "will comply"

By the way, most ATC simply use the word "Super" instead of "Super Heavy" as the callsign now.