Liam Neeson is a well known actor...but he's not an actor that almost everybody knows...if you ask everybody who mel gibson is they'll definatly answer at least that they heard of him!
Same with Christian Bale...he is a welll known actor now, but if you go and ask the public..."who is christian bale?" many will say that they never heard of him.
I still stand by my opinion that Harvey Dent/Two Face should be played by either Thomas Jane or Guy Pierce. Jane showed us intensity and rage as The Punisher, yet he was normal, sane, and loving as Frank Castle when his family was till alive. Pierce, IMO, is a dynamic actor altogether. Movies like Ravenous and Memento are examples of such talent......once again, IMO.