I think it's personal preference.
First you should ask yourself if you want to have a Stock ROM or a ASOP based ROM (like CM or ParanoidAndroid).
I personally prefer ASOP based ROMs. At the moment I use PA but I think about switching back to CyanogenMod because for me it's a bit more smooth.
But as I said thats just my personal opinion and you should test around a bit and find a ROM that fits best for you.