Sekai-Ichi Hatsukoi - Yaoi Anime about a (supposedly) "bi-curious" High School boy who confesses his love to a slightly older High School crush, then time-skips forward ten years to the same boy, now a man, who has given up on love, works as an editor for literature, but due to his own stubbornness at being the son of the CEO and not wanting everyone to think he slid in on his job, quits and becomes a manga editor, where the editor-in-chief is the man he confessed to in High School.
Oretachi ni Tsubasa wa Nai - Anime regarding several different characters, each with their own unique personalities, interacting with various people across a single city, and at around halfway through we find out that they are ALL, in fact, multiple personalities of a single person.
Steins;Gate - Mind Fuck Anime regarding a self-proclaimed "Mad" Scientist creating a device that can send text messages to the past, and who is the only person in the world capable of noticing the (sometimes drastic) changes that these time-texts have on the world.
Ano Hi Mita Hana no Namae wo Bokutachi wa Mada Shiranai - Anime about a group of friends whose lives diverged when one of them died in a river, beginning many years down the line when one of the friends can see, hear, and interact with the ghost of the girl who died. Anime concerns itself with mending the relationships between the friends, their families, and most importantly, with the dead girl to see her head to heaven.
Deadman Wonderland - Gruesome Anime about people given the ability to manipulate their blood into various unique shapes and forms, all very combative in nature, and a huge facility that keeps them that functions both as a jail and a public amusement park in the same area.