Well it depends on your preferences -
The EVO has a bigger, HD screen. The LTE connectivity is fast and the software (Android 4.0 with HTC Sense) is very slick and modern. It packs some serious hardware. Android does have occasional software issues and the app selection isn't at the iPhone level, but is definitely growing. The only true issue is that Sprint's LTE network won't be very widespread until at least a year after they start rolling it out (which could be a while).
The iPhone gives you great software performance, an excellent camera, and a good screen. It doesn't have LTE. The app selection is fantastic, and the media ecosystem with iTunes is perfect.
I would recommend the EVO. Android 4.0 is fantastic and you have some incredible hardware, an amazing screen, and a really cool looking phone.