I've seen many productions of this play on screen - Olivier, Branagh, Plummer, Chamberlain, Williamson. I've also studied the play and am used to thinking of Hamlet as severely depressed. He's the "gloomy Dane," is he not? Tennant's Hamlet is much more manic, say, than Olivier's or the agonized melancholic in my mind, and it took some getting used to. He embodies the ambiguity about Hamlet's madness. Is Hamlet crazy with grief, or is he feigning madness to distract from his plans to revenge his father's murder, or is the line between those two perforated? This is a great production, and I recommend it enthusiastically.