The new Tinker Tailor is legit, but tragically miscast. They had Toby Jones! They had Ciaren Hinds! Either would have been a perfect Smiley. Oldman (at that time) would have been a perfectly good Alleline!
If you haven't watched the BBC Tinker Tailor, you're missing out on the canonical Smiley, though.
Burton's Leamas in Spy Who Came In From The Cold is probably the GOAT though.