Nokia 7650 (2001)
A true pioneer for Nokia, the 7650 was the firm’s first phone to come with a built-in camera and the first to come with the Symbian S60 OS. The camera thing is a huge deal because, well, Nokia went on to make some of the best camera phones ever made (the N93, N95 and Lumia 1020 for starters) and S60 is significant because it quickly became the basis for the majority of the firm's more advanced smartphones.
What you can’t really tell from the image here is that the 7650 was a big old unit too, almost too big to be considered a comfortable phone. Watch the ad above and you'll get more of an idea of its bulk – as well as a bit of mild sexism courtesy of Nokia's ad agency.