Bongusta! The Phlog Aggregator.

Floodgap:
gopher.floodgap.com
Search using Floodgap's Veronica
"All the gopher servers (that we know of)"

New servers in Gopherspace
Local mirror (updated weekly)

Servers that are well known to be running:
Alive Servers

Observable Gopherspace Universe Project:
List of servers
Local mirror (updated weekly)

Related to nixers.net:
nixers community gopher hole
z3bra