Knights of Sidonia, Volume 1

I haven't read any of Attack on Titan yet. Nor have I seen any of the show. However, I have a really good understanding of the work's tone, and I think Knights of Sidonia pulls off that kind of tone better than I've heard Attack on Titan does. The action is gruesome, but it manages to do so without falling back on the same kind of beat over and over, which by accounts Titan does.

The monsters are visually unnerving, without the potential for the designs to become quite as unintentionally comic, as some of the Titan designs can be, due to the monsters being totally inhuman - Spoileruntil they kill a human and transform their appearance into a 30' form of that human..

Also, in this volume, while the body count is lower than the body count from the start of Attack on Titan, the stake's feel just as high, and the writers don't have to casually massacre hundreds of civilians to get the stakes across. Only one character dies in this volume, and it's enough to sell the threat.