Another vote for MIUI. Besides being a great performing\stable ROM, what draws me to it is the customization capabilities. You can change just about everything if you know how to use a paint program. I've already created my own custom lockscreen with music controls and themed the phone and message apps more to my liking.
The only thing to be careful of with the MIUI ROM is if you are on a limited data plan. I don't know about the newest releases, but the version I use (1.11.something), the build.prop file has the wrong version number and my phone was constantly trying to download the latest OTA. A simple edit to the build.prop file will trick Veriozn\HTC into thinking you have the latest OTA and it won't try to constantly download the latest update causing a huge usage in data.