Biggest feud of all time?

TheOneDylanThomas - BTT v/s Chutebox

This gets my vote. There was genuine bad blood between these two teams which, at the time, were maybe the two most dominant camps in MMA. Phone Post

 Ken and Tito's rivalry saved the UFC

Funaki Masakatsu #1 -  Ken and Tito's rivalry saved the UFC

Ken - Royce
Ken - Severn
Ken -Frye (not really a feud, but had real bad blood)
Ken - Tito
Ken - Frank :)

LOL.. Ken is a feuder.

Lucky for Tito he got the old/injured Ken.

Sukaraba versus the Gracie family Phone Post

Phan vs. Garcia Phone Post