Koisuru Tenshi Angelique: Kokoro no Mezameru Toki

Both are adapted from the Angelique series of games and thus, are both reverse harem. If you like one, you'll probably like the other. However, Neo Angelique is more serious and focused on action while Koisuru is focused on romance and comedy. 

Similar plot. An energetic but awkward looking girl is asked to save a land in crisis all while being protected by some fairly good looking guys.  

Each has a main character whom has a mission/wish to fulfill. They both experience the feelings of love and go through a journey with the people around them. Both main characters also try and help the people around them (Ange helps the people around her and a universe whereas Kobato helps people around her) They also have a plushy and are both similar in personality :) 

Similar plot - one girl is chosen to help in rescuing world in some way. Both anime: shoujo, fantasy, a bit romance. 

The both reverse harem, the boys have "special" powers and trying to protect the girl 

Both are reverse-harem anime based on Koei's Neo-Romance video games. 

Again, there's a girl that's surrounded by men and some of them fall in love with her. The guys also have signs like in Fushigi Yuugi - although they're aren't seen. They are the guardians of the elements. I really liked this anime and I liked Ange - she's really self-consciouss and gets embarrassed easily. 

Another creation by Koei, this is also a spin-off of a ren-ai dating sim for girls. There are 9 guardians of different elements who help Ange achieve the goal of saving the newly-born Cosmos. Sequel series is: Koi Suru Tenshi Angelique - Kagayaki no Ashita 

reverse harem