When the storyline "Planet Hulk" began running in Incredible Hulk #92 (2006), I was at the time a freelance employee of Marvel Comics working on the Official Handbook of the Marvel Universe and related projects. At the time, Marvel didn't supply me with comps of all their titles so I had to spend my own money on their new products. Usually I only purchased books which I needed for research and as our staff of writers had each eaked out particular corners of the Marvel Universe, the Hulk was one such character I could safely set aside. My friend Anthony Flamini had the Hulk material under control at the time as he wrote the book Planet Hulk: Gladiator's Guidebook.
I hadn't been reading the Hulk for a very long time - this was just after a brief, unlamented 2nd run by Peter David, but I hadn't followed the book regularly since that author's 1st run had ended the previous decade. Then and now, the Hulk was a character who I could enjoy, but it depended on the creators. The creative team for Planet Hulk of writer Greg Pak & artist Carlo Pagulayan made almost no impact on me. I knew Pak only for a revamp of Adam Warlock which I hadn't liked at all and Pagulayan I wasn't familiar with. The concept which was being promoted - that the Hulk goes into space and becomes a gladiator - didn't thrill me.
Fortunately for me, one of my areas of expertise in the Marvel Universe were the alien race the Kronans and I came into Planet Hulk when Kronans appeared in the 2nd chapter (I wrote an entry on the Kronans for the Marvel Appendix). I had previously thought Planet Hulk was using only new alien races and was pleasantly surprised to discover that although Sakaar was a new environment with its own history it had ties to familiar Marvel aliens like the Kronans and Brood. The trappings of the Marvel Universe can at times feel like they've been so set in stone that no new significant corners of said universe can be revealed without seeming out-of-place. Sakaar not only proved to have a very well-thought-out and interesting history which was slowly expanded on throughout Pak's stories, but also a unique mythos (everything to do with the stone priests and repeated mantras such as "Sakaarson, hear my cry..." or "May he who dies, die well.") and weight within the larger Marvel Universe via the use of the Brood, Kronans and Silver Surfer.
Pak was coming to the Incredible Hulk at a time when Marvel's comics were largely segregated from each other (although Civil War was primed to change all that). There was not a great sense of continuity from one creator to another as popular writers like Brian Michael Bendis didn't particularly care about whether their characterizations of Marvel characters held with prior interpretations. This is one way in which Pak's characterization of the Hulk was a nice surprise as Pak invoked continuity within Planet Hulk's first four-parter, noting how when the Hulk first met the Silver Surfer he had asked the Surfer to bring him to another world. This was some incredible continuity-fu Pak employed, giving added weight to the idea of the Hulk making an alien world his new home.
Pak has said at various times that his take on the Hulk's theme is "the price of anger" -- that however cathartic it might feel to see the Hulk tear down a deserving foe (namely the Red King in Planet Hulk), eventually there is a price for that violence. In the case of Planet Hulk, the Hulk's own decisions and actions set into motion the climax in which his queen Caiera is murdered, thus setting up Pak's World War Hulk and Skaar: Son of Hulk. Planet Hulk is a tragedy.
...And yet, it is a tale of many tones. There are spectacular action scenes of the Hulk and his Warbound surfing across a bed of lava and battling hordes of zombiefied Spike; there's the gentle humour of Miek in the early chapters, or the sardonic robot ARCH-E-5912; the fire-forged bond of friendship between the Warbound which helps the reader care for the Hulk's allies Korg, Miek, Elloe Kaifi, Hiroim and No-Name.
But yes, ultimately it's a tragedy. There are haunting images of Caiera holding a child which is burned until it crumbles in her arms; Miek's own tale is a tragedy run in parallel to the Hulk's as the Hulk doesn't see how Miek is adopting his values for himself and Miek's inability to cope without an enemy to fight leads to the greatest tragedy in the story's conclusion.
Then and now I give Planet Hulk high marks for the emotions it provokes in me. I enjoy the high adventure of seeing the Hulk as a gladiator, rebel and king; I love the Warbound, particularly Korg and Hiroim; the Silver Surfer's farewell to the Hulk is a heart-warming occasion; so is the Hulk choosing to become Banner for Caiera. Planet Hulk is ultimately my favourite Marvel super hero comic of the 21st century so far. If you still haven't checked it out, please do.