Chewing the Scenery...

[Willem]

I always liked John Lithgow's overacting in Third Rock from the Sun. Functional there too since he was playing an alien

[meerkat]

3rd Rock was brilliant. I think they all over did it!

[Quatermass]

More scenery chewing from Doctor Who. Here, Peter Davison makes us believe that the Doctor is a desperate man, not only saying this to Stotz (the man with the gun) but also to himself (it is hinted that he is holding back his forthcoming regeneration due to spectrox toxaemia from sheer force of will). "So you see, I'M NOT GONNA LET YOU STOP ME NOW!!!"

And from later in the same story, Sharaz Jek, who has spent the story alternating between quiet menace and insane yelling, finally gets his chance when his adversary, the one who caused his disfigurement, comes to track him down. Christopher Gable goes all out. "You think bullets can stop me now? You stinking offal, Morgus, LOOK AT ME!!!"