I'm sure all the droid geeks will chime in here about how much better the Droids are over the iPhone but I love my iPhone. I've had a 3G, 3GS and nor a 4S. My wife has a 4 and my daughter plays with my old 3GS.
Here is my likes and dislikes with the iPhone. I'm sure the HTC phones have similar specs.
Likes
1. Great OS. The iPhone is popular for a reason. It's simple to use compared to the Android OS which requires a learning curve. My 5 year old taught herself how to use the Phone. iOS just works intuitively.
2. Lots more apps. Think of something. There's an app for that.
3. Facetime video chat is cool if you have family with an iPhone or iPad. Great to share moments with far away loved ones.
4. Good camera in the iPhone 4. Fantastic camera in the iPhone 4S.
5. Retina display is amazing. Reading web pages is equivalent to reading on paper. No discernible pixels.
6. Find my iPhone. Never lose your phone again!
I've tried messing with the Android phones and they just are not intuitive. It's really the equivalent of a Mac and a PC. The PC is open platform and more complicated. The Mac is closed platform but easy to use.
Dislikes
Hmm... let me think. Maybe a bigger display and of course Flash support. A SD Memory slot would be nice to but that isn't going to happen. With iCloud, device storage isn't as critical. The biggest negative, is I now want an iMac and an iPad. $$$