Lucky☆Star: Original na Visual to Animation

Both are short little side stories to a school girl anime. Obviously, different ones or else these would be related series. 

As Haruhi is recommended from the main Lucky Star I feel that The Melancholy of Haruhi-chan Suzumiya - ONA should be recommended from the Lucky Star OVA. The latter is roughly 5 minutes per episode, but differs, and most important of all, it is absolutely HILARIOUS, in my opinion it is far superior to the second season. 

both really funny and really random