I prefer the regulars, I find I can eat far more of them in one sitting. The double stuff ones just wear me down with their excessive clagginess. The original Oreo is king.
I object hugely to Oreos, we invent the greatest buscuits in the world (plain chocolate Hob Nob anyone?) and some marketeer feels it necessary to introduce more crap from the US, then feel we have to be taught how to eat the things. Yuck.