Best "phone?" Motorola.
Best "cell phone plan?" Depends on your usage, including minutes day, minutes night, roaming, digital connect, etc. My old Sprint allowed me to connect to the web from my laptop, and never dropped a call, was limited to CDMA nets, and roamed in Montreal. My new Cingular coverage includes Montreal without roaming charges, but won't let me call the web (except for an extra $80/month), drops calls all the time, but works in most of the world.