The Guild Wars Challenge Mission Ladder houses the records of the most skilled challenge mission players, displaying the top 50 combined aggregate scores for players across all challenge missions. You can search this ladder by specific challenge mission or by Guild Wars campaign. Be sure to check the ladder regularly; its ever-changing, and you never know who you might see at the top!
Aggregate score is a calculation based on the ranks attained across all missions except those considered Special Events. Hovering your mouse over the aggregate score will show you the ranks attained on the listed missions. Missions with a dash are either unplayed or the Guild/Party did not reach a rank greater than 50 and are therefore disregarded when calculating the aggregate score. First place is worth 50 points whereas 50th place is worth one point. A perfect player or guild would have an aggregate score of 50 which is the maximum possible.