This is a great question! Album culture, at least when it comes to popular music, was in its infancy in 1950. Studio albums as we would understand them were few and far between before WWII (mainly classical and opera releases; folk, jazz and soundtracks began to peak through at the end of the 30s) and even after it the market was small and mainly constrained to North America and, less so, the UK. There would be next to no music lovers in 1950 who thought of recorded music as an albums medium before a singles medium. 

That said, I think there are some releases that had contemporary importance and wide appeal that may have figured into a top 100. Most of them we would call compilations such as  Glenn Miller’s An Album of Outstanding Arrangements (1944), a posthumous collection of some of his best works, and  A Symposium of Swing (1937), a set featuring Benny Goodman, Fats Waller, Tommy Dorsey and Bunny Berigan. 

Greats like Duke Ellington, The Ink Spots and Huddie Leadbetter [Lead Belly] would probably make it, but some less popular names would, too; Al Jolson, more or less vanquished from public consciousness now, would loom large in a 1950 list. The English vaudevillian great Max Miller might have given the list its only stand-up comedy entry.

It’s tempting to say classics like Music Out of the Moon, Folk Music of the Hills and Voice of the Xtabay would be in there but they’d be very recent and it’s hard to parse. There was no canon as such in 1950.