Google decided to release the Nexus One phone which probably one of the best Android device out there.  The device is available under T-Mobile or can be purchased to use with any sim card.  However, the Nexus one is not compatible with AT&T’s 3g towers for data so If you don’t have T-Mobile and live in the USA I am not sure what other carrier you would plan on using it on.

More info about Nexus One: http://www.google.com/phone