 If you liked
Trigun
|
 ...then you might like
Haibane Renmei
|
These anime are very different.
Especially, the first 16 episodes of Trigun. Those are mainly focused on action and comedy.
However, I think that from episode 17, Trigun shares a common theme with Haibane Renmei.
Being stuck in a monotone world, not knowing one's purpose. With no certainties. Somehow trying to do what's right. Being subjected to phenomenon beyond the comprehension of an individual. Struggling to accept one's fate.
Wishing to lead a simple life, somewhere far away, in the face of cruel reality.
Other than that, I find the graphics similar - both pale.
If you're looking for something featuring existential angst, this could be it.