List of Active Places
Back in the day there were websites that would list the numerous muxes, the theme, and sometimes even the current number of active players. Occasionally there was a graph showing things like login peaks and other interesting statistics. Do any of these still exist and are they still accurate? I feel like my favorite hobby is coughing out it's last breath, tell me it ain't so!
http://mudstats.com/ is probably what you want. Although it can take a while to get up a new game.
I still check the "New" and "Updated" section on MudConnector from time to time when I'm restless.
I don't know that I'd call it reliable, but I never felt like it was hugely reliable in terms of telling me if a game was active. Just if it existed and was up. A lot of games put up listings and then never get beyond the initial stage of Headwiz and Nobody Else Logged On, of course, but that always happened. Just looking at it now, hey, a Grimm place exists I haven't seen listed anywhere else.
I'll second my experience that Mudconnector is dodgy at best. I'm not sure of the algorithm that the site uses but the cached activity reports for games seems to be highly delayed. But its still possible to find some interesting places if you have the patience for sorting through things.