If you liked the Highschool of the Dead manga, the Anime-Planet community thinks you'd like:
In the not so distant future, the overpopulation and overfilling of landfills has led Japanese bioengineers to create Bio Meat, known simply as B-M, that eat trash, produce more of themselves, and can be killed for food. But when an earthquake frees some B-M from their containment center, the situation rapidly spirals out of control. With B-M eating everyone in sight, four middle school students flee the gruesome carnage found in their classroom and search for their parents and safety. Can brash Maaya, quiet Kanomiya, intelligent and cold Shingo, and always-eating Banba survive, let alone anyone?
If you liked the weak survival horror aspects of Highschool of the Dead, check out the far superior Bio Meat. Both have an equally as fragmented flow but Bio Meat is just way better on all levels.
High School of the Dead and Blood the Last Vampire have high schoolers fighting against the forces of the undead. Both series are action packed with the students trying to survive the onslaught of underworld beings.
In the near future, some girls are born mutated. Known as Diclonius, this new species is believed to have been chosen by God to wipe out mankind. Unlike regular humans, Diclonius have two horns on their head and ‘vectors' - invisible ‘hands.' Contained within a research facility unknown to the world, the Diclonius are experimented upon mercilessly; many die or develop a hate for mankind. One such creature, Lucy, is said to be the first of the Diclonius. She escapes from the facility, but while fleeing she takes a bullet to the head and is seemingly killed. However, it seems Lucy isn't quite dead yet; she's instead developed an alternate personality called Nyuu. She's washed up on a shore where two people, Kouta and Yuka, find her and bring her home, unaware that such a monster still lurks within Nyuu.
Action packed gore and violence are seen in High School of the Dead and Elfen Lied. Each series involving high school aged people taking on some element of the undead or supernatural. Both series with graphic scenes of the gore and ecchi nature for some entertainment.
A boy awakens on a desert island, unable to remember how he got there. He found the remains of a lifeboat with a few days’ worth of food, a survival kit, clothes and a trip schedule. Luckily, he soon discovers that one of his classmates, Chika, also is on the island. Together, the two catch fish, build a raft and try their best to survive and wait for help – not to mention try to remember how they came to be on the island.
Highschool of the Dead is based around zombies and people tend to get killed, while Let's Lagoon is more of a quiet tale of life on an island. What do they have in common? A combination of survival and ecchi, without an excessively harrowing survival tone like other series out there.
HSOTD has zombies, and Meteor has good old fashioned/realistic survival. What they have in common, besides the survival elements, is a horrible bastard of a teacher who cares only about himself and manipulates others for his own benefit. If you read one, you'll immediately recognize the char in the other.