So.. here's my list of phones in order of coolness :-)
N900 - The sickest phone on the market of course.

* N900 brochure page
* Wikipedia: N900
* Official Maemo software
Note that there is even more unofficial Maemo 5 software that is usually available at no cost.
So now that I have made my shameless plug for Nokia's phone lets look at the Android offerings which aren't as cool in my opinion but are more popular sales wize due to google's massive amounts of marketing.
Android is not a phone actually! Android is an operating system for mobile devices (phones tablets ebookreaders) and embedded devices (your refrigerator or in the near future your TV). Read here for more about what android is and why it is better than the iPhone OS, Windows Mobile and Blackberry.
* Wikipedia: Android OS
* http://www.android.com/
Click on the market button at the bottom to see available free and for pay applications. The Developer button there leads down the rabbit hole which is java/dalvik programming whoo!
Get on with the Phones man! OK! I will!
Where Android really shines for the end user is the choices of phones and the fact that most all Android programs run the same on any of them.
Some of the latest and greatest Android phones are the HTC Hero, Incredible and EVO 4G, the Motorola droid, the Google Nexus one and the HTC Droid Incredible.
Specs/Reviews:
Nexus one
HTC Hero
Motorola Droid
HTC droid Incredible
The Droid incredible is nearly Identical to the Nexus one but is sold only at Verizon.
HTC EVO 4G
Below is a video of Android Froyo 2.2 which most of these phone will run or update to.