I'm hesitant to pick in reality it's 50/50 imo, but to promote my support for Shoguns instant rematch I'll side with Shogun .
Anderson would win imo, he is a bit faster and more unpredictable. I think that would see him through.
I think Silva would knock Rua out. Silva is one of mma's most precise punchers, and his striking otherwise is at least on par with Shogun. Shogun does have the chance of getting Silva down, and trying win by grounding and pounding. I just think Silva will eventually catch Shogun with too many clean punches, and put him away. I think Silva is more capable of the performance many expected from Machida last night.
Shogun will neutralize Silva with his legkicks. Its a thing to catch Forrest or Irvin's kick, but Shogun is a total beast. + Shogun has the chin to fight vs Anderson.
Any good version of Shogun destroys him. The highly overrated Silva never wanted to enter into the dangerous waters at 205.
Theres a big difference between PRIDE Rua and UFC Rua even though he did win a title with UFC. I dont think many couldhave beat him during his PRIDE days including prime Anderson Silva but his time with UFC has been fairly mediocre with 9-8 record. His win over Gian Villante recently being his 3rd win in a row and only second time he has had a win streak in the UFC
Silva, better strikes and better ground game. I think Anderson picks him apart. Rua vs Wandy is more interesting.