Both has pluses and minuses, but in my opinion, for the overall package go with the Droid Incredible
Incredible notes:
HTC Sense looks and feels better than Touchwiz
Uses Google Search
You will get Froyo update soon after activation, since its already OTA
Its an HTC
Camera very good
Battery sucks
Neat flashlight app
Great software keyboard
HTC seems more prompt with their updates
Captivate
Uses Bing search (many unhappy about this although it is a relatively decent looking app)
Beautiful glorious and bigger screen
Plastic build but solid and impact resistant but not scratch free
A bit better on the battery life
Touchwiz is logical and easy to use, but many don't like it for being too iPhonish.
Comes with Android 2.1. May update to Froyo later, but Droid Incredible has it now.
If you update to Froyo, you can obtain the blue Google Search widget with Voice in the Android Market (yeah weird huh, this widget is Froyo only).
Comes with Swype?
