4. Jon Jones vs. Anderson Silva
While technically this fight still could happen it is pretty unlikely now. Silva is already passed 40 and Jones is looking at a possible 2-year suspension as a result of his most recent failed test.
Jones and Silva are the 2 fighters most commonly referred to as the best of all time, but now both have failed drug tests in the last 2 years. This fight would have been a chance to see the 2 greatest pound-4-pound greats of all time against each other, but the chances of us seeing it now are very slim.
