If you liked
Genshiken
|
...then you might like
Ore no Imouto ga Konnani Kawaii Wake ga Nai
|
The protagonists intially reject their Otaku nature through fear of ridicule.
If you liked
Death Note
|
...then you might like
Higashi no Eden
|
So if you were given a chance to change the world would you use it? Even if it meant people would die for your cause? Both series involves several groups facing off against each other in a life or death game to find out whose form of justice will prevail.
If you liked
Beck
|
...then you might like
Detroit Metal City
|
While both are very obviously music orientated, I wouldn't go as far as to say they are similar anime (Beck is slice of life/comedy, while DMC is more ironic). However I will strongly recommend you following up on DMC after watching Beck.
If you liked
NHK ni Youkoso!
|
...then you might like
Nodame Cantabile
|
Both focus on the hardship of college life and students trying to better themselves. The relationship between the two main protaganists are also similar (Noda helps Chiaka & Misaki helps Satou). Where one is trying to help the other, out of blind love, but is seen as somewhat of a nuisance by the other.