Galaxy nexus is a good option and as far as the dua/quad query, for a normal user not much of a difference, i just had a hands on HTC One X and it's good no doubt but the exorbitant pricing of this phone does not go in it's favour. i thought my GNexus was on par with it. checkout the test bench for HTC one S, it being a dual core beats quad core heads down.
It boils down to personal flavour. I prefer dual core because its more matured than quad core. But there are people that would say otherwise.
Sent from my Galaxy Nexus using xda premium