Recently just switched over from the long line of Verizon Androids (still have one, the Motorola Xoom which I honestly like more than my friends iPad) but I made the switch for these reasons...
1. Battery life is superb compared to MOST of the Droids on Verizon.
2. Screen is gorgeous.
3. Size.
4. Touch Screen.
5. Apps.
The only phone that I would compare to the iPhone on Verizon's line up is the Samsung Fascinate. It looks the closest to the iPhone, design and interface wise. Also, for the screen size, battery life is actually not bad. For a 4" super AMOLED screen, I could usually go a full day without charging, but with my iPhone normally I can go a day and half sometimes 2 days depending on usage. I thought having a HUGE 4" - 4.3" screen was awesome, but then comes the battery drain issue and how it fits in a pocket. I thought I would hate the size of the iPhone for it being small, but now that I have had it for 3 weeks, I picked up my Thunderbolt before I sold it and said "Wow how did I ever use this thing, its monstrous!" Touch screen sensitivity is out of the this world. Texting on my iPhone is easy once I got the hang of the keyboard ( I was use to swype which is the only thing that I miss). Apps, nothing needs to be said... biggest market for apps... period.
Edit: Once the Motorola Bionic comes out, if it comes out... I may considering picking on up on
eBay once the hype goes down and the price comes down, but again I do this a lot with phones but I have a feeling I will be sticking to my iPhone for a while. I am enjoying this phone so much, I actually convinced both my Mom (long time blackberry user) and girlfriend (fellow Droid user as I was) to get iPhones as well.