When I was learning how to play blues harmonica back in the late 1970s, websites like Modern Blues Harmonica didn't exist. The world wide web didn't exist; iTunes and Amazon and YouTube, with their marvelous search engines and repositories of new and archival material, didn't exist. What existed, at least for me, were the record bins in my local suburban mall and, later in New York City during the 1980s, the record bins at Tower Records, Colony Records, and HMV.
Nevertheless, I managed to accumulate a remarkable amount of good recorded harmonica music, 95% of it in vinyl form. Although my knowledge of what's out there--particularly on CD--is by no means comprehensive, I do feel qualified to offer some suggestions. Each of the albums below has a treasured place in my personal collection. I didn't just listen to these albums repeatedly; I jammed along with them repeatedly, harmonica(s) in hand.
And please note: I didn't just listen to harmonica players. As you'll see below, the lower portion of my recommendations consists of sax players, pianists, vocalist, and guitarists. One of the ways I deepened and stretched my musicianship was by listening to a range of other singers and instrumentalists who moved me, striving to translate their licks into things I could play on the harmonica, and jamming along with their soulful grooves.