Tom Cruise is actually a very good actor - he just gets up people's noses because he specialises in playing cocky, arogant, alpha male types (this is taken to its logical conclusion with his part in Magnolia).
As for the over actors - this is not always their fault. Al Pacino is more than capable of giving a subtle performance (see Godfather 1 and 2) - it's just that after Scarface every director decided they wanted "crazy Al",all the downplayed takes probably get left on the cutting room floor. I expect he's bored of it too.
Charlie from Casualty doesn't look anyone in the eye - I can't work out if he is a good actor playing someone who can't look anyone in the eye, or a bad actor who can't look anyone in the eye
