O2 XDA, indeed
Far more worthy of inclusion than the flopped N-gage handsets, the first HTC Windows Mobile phone, the O2 XDA was at least as revolutionary as the first iPhone, only without the hype.
It wasn't *my* first smartphone -- I jumped aboard with the O2 XDA II. It served me well for many years. The first in a long a still running string of relevant full touch-screen phones that spelled the end of the stand-alone PDA.