One of the best could be 'The Dark Knight Returns'. It presents a gritty, aged Batman coming out of retirement in a different take on the DC universe. Another might be 'Kingdom Come' which shows a future where the superheroes' ideals have become corrupted. 'Red Son' is also great, with Superman landing in the Soviet Union instead of the United States, leading to a very different world dynamic.
Batwoman is portrayed as gay in comics. Her sexuality is an integral part of her character and has been explored in various comic issues and storylines.