Recommend me Muddy Waters

I'm reading John Fahey's book about the emergence and history of the Delta Blues (Charley Patton+) and I realise I don't have any Muddy Waters albums.

Shame on me!

Heard some early stuff today playing on a Dylan Theme Time Radio prog, something about walking, fantastic backbeat.

So, which ones, and why??

Vinyl or CD - both useful.

Thanks in advance.