Let's not forget the cinder block (600) series Macs. Ugly, heavy, and tend to leak lots of bar oil, but they are pretty tough. Mine still runs even after being thrown (long story...) and kicked (another long story) Leaks bar oil all over God's green earth though. Which that oil tank leak may explain why it runs good for some time, then quits. Let it sit, it'll run for a while, then quit. Over and over again... still keeps on running. That's better than a saw that doesn't run at all, lol.
I would second the 10-10. I keep hearing about these "little" 50cc class muscle saws pulling chain forever... I need to find one someday. However, I've already gotten bit by Yellow Fever again, just 30 some minutes ago... More on that tomorrow. And it probably is one of the most reliable saws. (what properly taken care of old American mag saw isn't?)