I love shounen manga, American comic books, and American superheroes. Especially when it's a team of characters with different strengths and weaknesses working together. Super Sentai is a live action superhero team show with Japanese design sensibilities, and that appeals to me for several reasons.

...so yeah mostly it's the characters and the team dynamic. If a show has great action, cool villains, or a good story it's icing on the cake, but I really have to enjoy the team to enjoy a show.