Alright.....here it is......the UMC, ELCA, PCUSA, Episcopal Church.
Basically these are the biggies.....mainline means biggest of the Protestant denominations (they tend to be the most liberal).
There are more conservative branches of these churches that are not considered mainline, such as the Presbyterian Church in America or the Lutheran Church (Missouri Synod).
And movements within some churches to battle off the non christians and save our denominations. The "Confessing Church Movement" within the PCUSA is one example.
Thanks :)