Goethe famously said 'If one wants to know Shakespeare whole, read Troilus and Cressida'.
Above all else it is one of the great ensemble plays, so allows so manycasting possibilities, unlike say Macbeth which in effect is a two hander. So how about:
Troilus - Sam Crane (glad somebody else admires this great young actor)
Cressida - Emma Watson
Cassandra - Judi Dench
Pandarus - Stephen Fry
Ulysses - John Shrapnel
Nestor - Alan Bennett
Achilles - Dominic Cooper
Patroclus - Ed Speleers
Hector - Denzil Washington
Thersites - Ian McKellen
Priam - Richard Corderey
Paris - Lex Shrapnel
Agamemnon - Richard Griffiths
Ajax - Clive Wood
Andromache - Zoe Wanamaker
Menelaus - Rupert Everett
Helen - Victoria Beckham
Calchas - Michael Gambon
Diomedes - Daniel Radcliffe
Dream on!