They both are amazing divices, but i would personally recommand u the EVO. Because I've been using HTC HD2 "kinda EVO" since it's launch and it works pretty awesomely. Not to mention the massive screen which blows everyones minds when they see it. One piece of advice though since you are new to smartphones, don't expect the EVO to be "perfect" out of the box. If you buy such a device you gotta spend time with it, tweak it, modify it, make it yours. The Xda-developers is the heaven for smartphones where you will be spending most of your time when/if you buy it. :D

Cheers