If I had to remove one of the actors listed, it would have to be Al Pacino. His best work was definitely in the past. I can't think of one role that's been stellar in since his tandem film offerings, The Insider and Donnie Brasco, and both of those were in the late 90's. I did like him as Shylock in the The Merchant of Venice from 2004, but it wasn't anything special.
As to his replacemet... I had a really hard time coming up with one, because every person I would have selected is already on this list. But then it hit me, I've yet to see a bad performance from Javier Bardem. Even in somewhat lackluster films such as Vicki Cristina Barcelona, Love in the Time of Cholera and Goya's Ghost, he's been the lone ray of sunshine, it what I considered lightweight films. He was outstanding in The Sea Inside, Biutiful, and No Country for Old Men, the latter which, won him an Oscar. Along side Daniel Day-Lewis and Philip Seymour Hoffman, he's one of those rare actors today, whom I trust implicitly to find a good role and to make it his. I'll definitely see one of his films, just for his performance and that's not something I tend to do with other actors. Only the three I mentioned.
So Al Pacino is out and Javier Bardem is in. Here's the revised list...
Philip Seymour Hoffman
Samuel L. Jackson
Al Pacino Javier Bardem
I pass the baton to Oldkid