That's a good question. Have you tried out the HTC Droid Incredible? Its probably the oldest of the leading Droid Smartphones in the Store, but its still a very nice phone. Its got the smoother edges and slightly smaller form factor than the Giant-that-is-the-Droid-X, yet it feels more solid than the Samsung.
As to the youngest of the leading smartphones with Verizon, that's easily the Droid 2 Global, but as that's a cousin of the Droid 2, I would say the Samsung Fascinate. It has yet to receive the latest update to Android 2.2, so the full potential of the device hasn't been reached. Seriously, Android 2.2's base processing code really makes Android just ZIP along compared 2.1 and earlier.
How do you feel about the DroidPro? Its made more for Business users switching from a Blackberry or Palm device, but its also fairly new.