I still carry my old Nokia 5185.
It makes and receives telephone calls pretty much everywhere. What else does a telephone really need to do?
The T18 and T28 were a pain. There was a software bug in them that made it look like the phone was operating normally, with full signal, until you try and call or text.
Rebooting the phone would make it spring to life, letting you know of all the texts and voicemails you had waiting for you.
Admittedly I did like my Motorola mini-brick in the mid 90s, with the pull-out aerial and the flip, but it was a bit chunky, and basically too big for a pocket. So it was belt clip time - not the most elegant look.
I had some lovely green screen Nokias. Huge battery life, and great call quality.
But the phone I liked best, was the Original V3 RAZR. The flip meant that it was protected in your pocket, and you couldn't accidentally press buttons. That also meant you didn't have to have a key lock, so you could just pick it up and use it, without fiddling. Nice big buttons, for my fat fingers. Big screen, so big text, for my dodgy eyesight. Not that small a phone really, but thin and folded in half, so really comfortable in the hands, and tough (mine took a lot of abuse). Battery life was a bit poor because of the screen though.
It's the only phone I've really loved. The Nokias were great, with week long battery life. But didn't look nice, and weren't as comfortable to use. It was elegant design, in that it looked good, but function dictated the design decisions.
I think if I could have my perfect phone, it would be a Razor, with green screen / e-ink (for battery), 3G/4G and WiFi so I could use it as a modem/access point for a tablet. Monochrome sat-nav and a text only email client.
Except it's a 6610i for me...I think it's 7 years old, and the case it a little tatty, but it still works fine, holds its charge for 5 days, and gets reception in most places modern toyphones don't.
One day it's going to disintegrate finally, and then I'm going to be toiling