For live games, my observation is we don’t need a bunch of filters, on KGS at least, people pretty much just pick one of the top few games on the server and hop on to kibitz about it. Because of that, it’s been our long time intention to do a sort of “OGS TV” system, borrowing from “Lichess TV” concept, which is basically a special page that always has a top rated live/blitz game for kibitzing on, when it concludes, it automatically loads up the next one. With this same system we also want to add embedded twitch.tv support to make it easy for folks’ to see ongoing lectures or other go related twitch tv content and the like.
For correspondence games, some more filtering would be nice, but each search dimension is at least another index, so basically we just need to par that down to what people actually want to search by, not just add everything.
What I definitely want to do is add a “favorite player” system so you can easily see a list of games by all of your favorite players, both correspondence and live. But that’s somewhat of a different system all together.