Unalone's enjoyment of Finnegans Wake notwithstanding, deciphering the footnotes and expository ultimately doesn't have the upside that learning the English of Shakespeare and Chaucer do.
I'd suggest readers try Joyce's wonderful short stories, then making an assault on Ulysses. Nabokov, a Joyce admirer, called Wake, "that petrified superpun."
Beckett, on the other hand, who was Nabakov's moral and intellectual superior, developed his style as an antithesis to Finnegans Wake and cited it as his greatest inspiration.
Ulysses is similarly a masterpiece, but if I could only pick one it would be the Wake. It's a testament to the power of language. I've always seen Lolita as a lesser Wake, actually. It does nothing as original or quite as beautiful, though it comes close with its opening passage.
I'd suggest readers try Joyce's wonderful short stories, then making an assault on Ulysses. Nabokov, a Joyce admirer, called Wake, "that petrified superpun."