Fall of the Hulks (optional)
[I'm only including this story because it features some X-Men. This is a 99% Hulk story, so it's completely optional from an X-Men point of view. Also, the beginning is a bit confusing because most things are explained via flashbacks throughout the event. There is a lot of issue-splitting because there is a lot of stuff happening concurrently.]
Fall of the Hulks: Alpha
Incredible Hulk v2 #600 (1st story)
Incredible Hulk v2 #606-608 (2nd stories)
World War Hulks (Red She-Hulk story)
Fall of the Hulks: Gamma
Fall of the Hulks: Red Hulk #1
Fall of the Hulks: Red Hulk #2 (p. 1-15:3)
Incredible Hulk v2 #606 (1st story) (p. 1-26)
Hulk v2 #19
Incredible Hulk v2 #607 (1st story) (p. 1-18)
Hulk v2 #20
Fall of the Hulks: Red Hulk #2 (p. 16-end)
Fall of the Hulks: Red Hulk #3-4
Fall of the Hulks: Savage She-Hulks #1
Incredible Hulk v2 #607 (1st story) (p. 19-end)
Incredible Hulk v2 #608 (1st story) (p. 1-10)
Hulk v2 #21 (p. 1-7)
Fall of the Hulks: Savage She-Hulks #2 (p. 1-5)
Hulk v2 #21 (p. 8-12)
Incredible Hulk v2 #608 (1st story) (p. 11-17:4)
Hulk v2 #21 (p. 13-16)
Fall of the Hulks: Savage She-Hulks #2 (p. 6-13)
Hulk v2 #21 (p. 17-23)
Incredible Hulk v2 #608 (1st story) (p. 19-end)
World War Hulks (optional)
[Direct continuation of the story above]
Hulk v2 #22 (p. 1-17:2)
Incredible Hulk v2 #609 (1st story) (p. 1-7)
Fall of the Hulks: Savage She-Hulks #2 (p. 14-end)
Fall of the Hulks: Savage She-Hulks #3 (p. 1-11)
World War Hulks: Spider-Man Vs Thor #1-2 (2nd stories) (optional)
Hulk v2 #22 (p. 17:3-end)
Fall of the Hulks: Savage She-Hulks #3 (p. 12-end)
Incredible Hulk v2 #609 (1st story) (p. 8-end)
Incredible Hulk v2 #610 (1st story) (p. 1-12)
Hulk v2 #23 (p. 1-34)
Incredible Hulk v2 #610 (1st story) (p. 13-end)
Incredible Hulk v2 #611 (1st story)
Hulk v2 #23 (p. 35-end)
Hulk v2 #24
These stories occur in Part 14 of the chronology.
I'm going to read a couple more things before advancing the chronology with HoX/PoX.