Everyone loves a good excuse to dress up.
After 2015's banner year for athlete costumes, especially in the NFL, the bar was set high. Just a mask isn't going to get you on this list; you need full commitment, and these athletes had it.
Now it's up to you to rank them:
Of course, there were other athletes who probably could have cracked this list. The Cleveland Cavaliers held a party that featured a host of solid costumes, as well as some props and cookies the Golden State Warriors considered rude.