for me was the halloween event. you could play in the arcade mode and win unlocked dead man crates just by collecting the candy crates in match. or, if you so desired, you could buy the crates. this was a great lead in to the next season, and based on the free stuff i got out of the halloween arcade mode, i was more than happy to pay for the season pass.
F... Yeah all in it from running wild to colect small crates and candy to get more equipment. That time i play like a maniac!