(I will copy-paste part of this answer, as I’ve recently had it before)
Haruhi, or Railgun, or Yuru Yuri, or Non non Biyori.. Too many to choose from! The common theme among these series that I prefer these shows to be laid-back, without much stress or drama. Slice-of-life anime are fun to watch, and to me they kinda feel like kids shows for teens/adolescents. If you go to anime conventions and you see 20-25 year olds dress up as cute characters from anime shows xD… We all want to retain a bit of the good parts of our childhood, until we are no longer allowed to do so.
In the picture below, I am wearing part of the costume of Homura ^^… I cosplay as her at anime conventions sometimes. Maybe I am wearing a special underwear?