Still running a 2009 AirPort Extreme at our house. I haven't yet brought myself to replace it, even though I'd probably see a significant benefit from 802.11ac support and better ipv6 support
It has been reliable for nearly a decade with barely a few thoughts. Much more than I can say about any previous router I had.
I can't decide whether to go as open-as-possible-but-more-expensive, or with something like Ubiquity, or what.