You know, I've always kind of dismissed UU. Not sure why. Having taken a look at the website for our local congregation it actually sounds way better than I've given it credit for. Might have to check it out.

+1 for UU. I'm not formally a member, but as far as churches go it's one of the few that I know of that atheist me might be able to tolerate. If you would prefer Xian, Jesus-y content with your (still quite-liberal) church, another to consider would be the UUC: https://en.wikipedia.org/wiki/United_Church_of_Christ . Also Unity: https://en.wikipedia.org/wiki/Unity_Church . 'Unity describes itself as "for people who might call themselves spiritual but not religious."' If you ever are in the KC area, Unity Village is a nice place to visit, the church has a beautiful campus there.