From the PlanetXbox360.com feature list:
"Narrowing the top five games of May, and putting them in order, was a complete bitch. Deciding between the top spot and the #2 slot was very difficult and anybody whose been following gaming news will know which two titles are there. Plus, there were a few games I had to leave off that I did not want to. If my chronic OCD would have allowed it, I would have made a “Top 7” list, but alas, I am held prisoner by my demons. Oh well, read on for our full list."