Really mysterious, with action, thrills, sudden twists of plot and people with special psychic abilities. Secrets labs, fights, mysteries, every volume ends with answers and yet more questions thrown at the reader...I know it's a bit vague, but I'd really appreciate finding more manga titles like those two. 2m705o

ETA I've read Elfen Lied as well (by the author of GnB).

I would suggest Noblesse. There's a lot of action (fights), experiments (who attain special powers and came from secret labs), and humor. It's long, but its characters keeps you entertained.

Mew, mew~ Mew~
-Mew

I have no clue what I'm doing

I'm also looking for manga's that are similar to Gokukoku, it's pretty much my favorite manga spat the moment.

I haven't read those two, but maybe:
Psyren
Mahouka Koukou no Rettousei
To Aru Kagaku no Railgun
City of Dead Sorcerer (magicians rather than psychics, but close enough)
Aphorism