For me, it must be Strikeforce folding its business. From how things played out for Bellator after their closure, I feel like Strikeforce just gave up right before things may have blossomed a lot better. I have no doubt that businessman involved with the organization must have received a good compensation, but it really comes across as a lesson to not quit when the victory that you've been seeking is just around the corner. I always felt that Pride was better than UFC, sentiment shared by Anderson Silva and Dan Henderson, for example. I thought WEC was below UFC and PRIDE, but perhaps on the same level as Strikeforce, before it acquired the service of Rousey and Fedor and Overeem and all the stacked heavyweight division, not to mention who knows if Gina Carano may have returned at some point and we would've seen Cyborg versus Rousey had they stayed together under the same umbrella. Bellator does have some interesting fighters, such as King Mo, Ben Askren, Chandler and Eddie, and perhaps some more, but their divisions are as shallow as a pool of water after a short rain, and I fear that they will never be really as good as any other aforementioned organizations. What is your if you have any?