Anderson Silva, altho Jon Jones will probably be #1 eventually. He just needs some more time and more wins. Thats the fight they should make tho, Silva vs Jones. I think as Bones gets older and bigger, making 205 might become a problem for him. So they need a Spider vs Bones fight before he becomes a heavyweight
Jones is going to be the guy to take Silva out. I cant stand Spider but he has had a good run which isnt going to last forever. I think with a win over the Spider, Jones will being what will be a long reign at #1 ranked fighter in the world.