If you liked the Tekkon Kinkreet anime, the Anime-Planet community thinks you'd like:
Unbeknownst to humans, demons from an overlapping dimension walk amongst them in the streets of Tokyo. The balance between the worlds is kept by the crow guardian Karas and Yurine, its master and voice of the living city. However, the time of harmony nears the end as the once-Karas Lord Eko returns. Seeking to purge humanity for its evils, he terrorizes the city with his minions that feast on human blood. The ultimate battle between good and evil awaits; can Yurine and her newly initiated Karas prevail against Lord Eko and protect their city against his monstrous horde?
Looking for something way better than Tekkon Kinkreet? I didn't care much for Tekkon, but Karas has a similar type of story: a man wants to single-handedly make a city "better", regardless of the cost. Karas is 500 times more badass and gorgeous, has a plot that isn't hands down confusing, and overall is way better on every level. If you liked Tekkon Kinkreet, check out the far superior Karas.
In present-day Japan, Toshihiko Momota is member of a secret warrior faction called the Kifuuken. The Kifuuken is dedicated to destroying Shokujinji - humans that turn into man-eating monsters when hunger takes them. However, to fate's chagrin, Momota meets and quickly falls for Yuka, a Shokujinji herself! Will their love be able to overcome Yuka's insatiable appetite for human flesh, or will the couple be destroyed by the bestial tendencies of humanity?
Tekkon Kinkreet and Kemonozume feature two mismatched protagonists and their seemingly impossible plight against a huge crime syndicate/secret organization. The plot is sort-of grounded in reality, with some fantastic elements thrown in, but the climax comes straight out of nowhere, and is completely, over-the-top bizarre. I'm still not sure how I feel about that. Also! The characters designs are in the same style, and there's quite a bit of gore.
Koto, A and Un traverse a colorful, bizarre and alternate Kyoto, causing plenty of collateral damage along the way. They’re looking for a special rabbit that can possibly help them get home, but plenty of challenges stand in their way including a robot, the meddling Council of Three, and endless exploration yet to be done!
Although Tekkon Kinkreet's plot is slightly more coherent than Kyousougiga, if you liked the use of wild color and movement in either show, you'd probably like the other. Additionally, both shows involve young protagonists moving through bizarre city landscapes.
Set in the not so distant future of troubled Tokyo, no job is too big or too small for the Danger Service Agency, as long as danger is involved. The crew is made up of an unlikely team of misfits: Mikura, a girl with a flair for guns and a love of martial arts, Kurokawa, an old man/ex-detective addicted to noodles, Harada, an engineering nut, and Asami, a schoolgirl. Unfortunately, no matter how small or simple job appears to be, the Dsa team always find themselves biting off more than they can chew...
Both Mezzo and Tekkon Kinkreet feature very fast and stylized action and loud coloring. Tekkon Kinkreet is a more psychological anime while Mezzo focuses solely on the action, but they have a similar atmosphere. If you like the atmosphere of one, I reccomend that other.
In the town of Cahmphon, an experiment of Dr. Franken's goes terribly wrong, creating a monster called Noiseman. Under heavy oppression, a group of young people rebel against this creation, to save the town, and the sound from being literally vacuumed away.
Animation-wise, there's no mistaking that these two are the product of Studio 4C. With incredibly detailed and rusty-looking objects and buildings, each is a treat to look at. In addition, both have an oddly-paced and confusing story, though Noiseman is much shorter than Tekkon Kinkreet. If you liked one. try out the other.