Gay friendly denominations:
United Church of Christ -
http://www.ucc.org/ (Track record for liberal activism. When Anne Rice left the Catholic Church again over homosexuality, they sent her a letter asking her for fellowship because they accepted gays.)
Unitarian Universalist Associations -
http://www.uua.org/ (Pretty much ideal for a gay person of any religious persuasion.)
Unity Church -
http://unity.org/ (I plan on attending one of these congregations. Looks to be ideal for the gay Christian.)
Evangelical Lutheran Church of America -
http://www.elca.org/ (Very upper class crowd here, from my experience. Upper class means better educated and more temperate when it comes to social issues. Though missional, they're still pretty apolitical for the most part. Members tend to be democrats.)
Other (not necessarily total tolerance, but moderate enough you can attend, be openly gay, and not get canned):
http://www.umc.org/ - United Methodist Church (very neutral atmosphere. some people will be very liberal, some people will be quite conservative. loving community overall.)
http://www.abc-usa.org/ - American Baptist Churches (MLK's denomination. known for it's political liberalism.)
http://www.disciples.org/ - Christian Church / Disciples of Christ (never been to one of these, but a friend of mine says its very moderate to liberal)
Churches to stay away from:
Roman Catholic Church - No explanation.
Eastern Orthodox - I assume they take the same stance as the Western church.
Plymouth Brethren - Expect to get canned.
Any Presbyterian Church - Expect to get canned.
Any Pentecostal Church (Assembly of God, Church of God, etc.) - Expect to get canned.
Non-denominational evangelical churches - Expect to get canned.
Episcopal Church in America - Used to be moderate, now they've gotten tight about homosexuality.
Lutheran Church - Missouri Synod - Very conservative twin of ELCA.
Calvary Chapel - Super conservative. Expect to get canned.
Evangelical Free Church - Expect to get canned.
Southern Baptist Convention - Yeah. You already know.