Inu Yashiki
"Inu Yashiki has a family, a wife and two kids, none of which care about him. When he learns that he has only three months to live he realizes that the only one who will miss him is his dog. Shortly after this realization he is killed in a crash landing by aliens. He is rebuilt by them as a machine with a human exterior. How will his life change now that he isn't human?" - Original Description
This manga is by the same mangaka who created Gantz, and isn't about lots of action or fan-service, but drama, emotions, and how Inu Yashiki comes to terms with and what he decides to do with his now newly given life. Don't mistake this as meaning there isn't action, but it's not the focus, it's likely Inu Yashiki's sense of justice (or his archenemy??) is what will have you coming back for more. As this manga is written by Gantz's mangaka, you can expect highly-detailed quality drawings.
http://mangasee.co/manga/?series=InuYashiki&chapter=1&index=1
(Click here for larger image in new tab)