I have always been interested in decoding varius digi modes on HF, it all started when I used my fathers ERA microreader to decode basic modes like RTTY and CW.  That was when there was allot of RTTY stations.  Now most stations have went to satellite communications or the internet.  I find that what is left on HF is heavily encrypted.  So these days HF FAX, SSTV, PSK31, RTTY and CW are my main focus.

HF-FAX images received with JVComm32

SSTV images received with MMSTV/HRD