If you're looking for anime similar to Melancholy of Haruhi-chan Suzumiya, you might like these titles. All recommendations are made by Anime-Planet users like you!
In a time filled with wars, environmental concerns and issues, there lives a gaggle of beautiful boys that are the personification of the world's countries. Japan, England, France, Finland, Germany and the rest of the boys attend the World Conference and tackle issues like global warming with a heavy dose of fun. Through multiple world wars the gang will traverse deserts, build mecha U-boats and solve the world's problems together!
Hetalia, like Haruhi-chan, is made up of short episodes, each with often simplfied, frequently bizarre, humorous scenes. Characters are stereotyped for humor, etc. I reccommed giving Hetalia a try if you liked Haruhi-chan at all. Each ep is only five minutes long anyway, so you may as well give it a try.
This spin-off of the Haruhi Suzumiya series takes place in the world of the "Disappearance" arc of the original novels, focusing on the high school life (and romance!) of a tentative and bashful Yuki Nagato quite unlike the one you've come to know and love through the usual exploits of the SOS Brigade... but no less charming!