FTP, Telnet, WAIS, Gopher, Archie, Mosaic, and all the rest were fun and fine.
But to me, it all really began (and will probably end) with The Whole Earth Lectronic Link
(aka The WELL). Still
clunky by design
, IMO it's the absolute triumph of content over form. And one of the few things that predated (and later transitioned over to) the web that's still worth keeping. Maybe one of the few things worth keeping on the web regardless.