I started re-reading GANTZ and ended up getting into it. I'd previously read through volume 15, at which point I was caught up and had to read weekly installments in Young Animal (or is it Young Jump?) and fell away. Now it's up to vol. 24 or 25, so I've got a little reading ahead of me. Luckily a media rental place across from my work does comic rentals for 90 yen a week.
Other Japan-bores: I've only seen this one shop do comic rentals. Is this common?
GANTZ is interesting in that it stays fairly realistic in depicting people's reactions while placing them in an insane situation. There's not a lot of melodrama, and people trying to be heroic are sometimes punished for their altruism brutally, and some situations are so overwhelming that even people trying for heroism sometimes flee in terror or freeze up.
Oku has been criticized for his overly dry, non-exaggerated rendering style, which is influenced toward the austere by his use of laying out every panel in a 3D CAD program, then tracing it. It does lend a cold, reserved, and somewhat photographic tone to the art, but I find that its very dryness lends to the believability and immersion, much like Lovecraft's first-person, reporterlike style in his mythos books.