I really like the simplicity of the Mission style Churches here in the Southwest. Some here are still made from adobe, others are built like the Mission churches but of concrete brick.
Almost all have some paintings on the ceilings, have statuary of Saints and other ornate decorations inside. Some have stained glass windows, others do not, especially the older ones.
Now if I had to go with something else, I think I would choose something like Hagia Sophia (the church in Istanbul that the Turks have made into a museum). It also has a simplistic beauty of architecture with nice lines outside and beautiful mosaics inside. It is more along the lines of a Greek Orthodox Church.