Round 1, Round 2 and Round 3 are complete for WWE.com's Greatest Faction Tournament, and we're down to the final four for our own brand of March Madness!

WWE.com invites the WWE Universe to participate in the final four of our tournament to finally decide what faction is the greatest of all time. (View larger & updated bracket)

The semi-final round features dream match-ups like DX vs. The Shield and The nWo vs. The Hart Foundation! The outcome of each battle is entirely in the hands of the WWE Universe.

Take a look at the matchups and vote for your favorite factions in the polls below as they battle to be crowned the greatest faction of all time. The faction with the most votes in each respective matchup will advance to the next round, so vote wisely.

Semi-final voting ends this Thursday as the championship begins.