Add Gegard Mousasi to the list alongside Fedor and Nog. This was Gegard's first combat discipline before doing boxing and before doing kickboxing and MMA. You could still see it through his trips and sweeps.
The same is true now as it was in 1993, BJJ is the basis for anyone serious about competing in mma. If you're not already a US national level wrestler, you're going to need the defense when you face one. If you have a strong wrestling base, you'll need the submission knowledge. Judo is a fine supplemental art, but I wouldn't worry about that for a while if you're just starting out. BJJ would rank first for me. If you don't have a striking background, I would suggest Thai Boxing next. Once you're proficient in bjj and thai boxing you could look into freestyle, greco-roman, or judo. Depends on what available in you area. Then you could look to tighten up your by working on boxing.
