Aa! Megami-sama! (TV), Tenchi Muyou! Ryououki Recommendations
Both have the male lead surrounded by beautiful girls who want to be with him. Both try to fight to help the female characters. Male characters are alike in all aspects. The only thing is separate is goddesses and extraterrestrials.
They are similar because the male protagonist meet a girl and more come. They both have many girls in one house with super powers. both funny and enjoyable to watch.