Darklink286 said:20th Century Boys, which is also by Monster's author and has live-action version that follows it nearly exactly no really I'm not kidding
Henry Spencer said:20th Century Boys - science fiction mystery. Awesome stuff, if you want something different.
I'm just beginning Volume 22, and I have to agree I really enjoyed this manga! I would recommend it!!
(I guess both of you include the last 2 volumes, known as '21st Century Boys', under the name '20th Century Boys'?)