That's an entirely different point you're making then. Nobody said he's as great as Joker or Ra's. Though, what has Ra's done that's as great as the Joker?
Two Face killed Carmine Falcone, Jason Todd's dad, was Batman and Jim Gordon's friend etc. He's hardly overrated. Two Face also has a great psychology to him.
Not really, the point of the thread is who do you think is the most overrated Batman villain. I see Two-Face as being overrated, but that doesn't mean I think he's a poor villain or not deserving of praise.
I'm not trying to say that Ra's has done anything that's as great as the Joker, but I am saying that these two are on a different level than all the others, including Two-Face who is only slightly behind them anyway.
Joker can't be touched in his number one spot, I think that's agreed in general, we know that. But Ra's has in the past proved to be a massive threat to Batman and the world in general. The numerous times he's tried taking over the world, kidnapping Robin, hitching Batman up with his daughter as well as being a threat to the Justice League.
Take nothing away from Two-Face, he's great, but behind these two.