The most faithful to the text is the 1996, Kenneth Branagh, Hamlet. The production is over-the-top opulence and Branagh can get annoying. A real sleeper is Campbell Scott's Hamlet. It has its weaknesses (the Ghost, Laertes) but Scott is excellent and the play-within-the-play is best on film. Mel Gibson's version is substandard. Laurence Olivier's Hamlet is competent though grossly simplified. I haven't seen David Tenant's Hamlet all the way through so I can't say on that. Ethan Hawke's is abominable. There are many others: Jacoby, Burton, Kline, Williamson, Plummer.