What /u/No-Pudding-8525 said. If you're interested in all the titles - and not just select ones - then your best bet would be the chronological TPBs they've released.

At the moment, you have ...

• Dawn of X - Volumes 1 through 16
• X-Men: X of Swords (Crossover that bridges "Dawn of X" to "Reign of X")
• Reign of X - Volumes 1 through 19 (although we're up to just about 14)
  • Just to note, there are separate special editions for the "Hellfire Gala" - but all issues were included in the Reign of X volumes
• Inferno