Russia is pushing its Su-30MK, the latest version of the Su/27/30 line of aircraft, as the most lethal air superiority fighter in service. This is part of a marketing effort to sell even more of an already popular aircraft. The Russians point out that the Su-30MK can fly as fast as the F-22, and is more maneuverable. What the Russians play down is the fact that the F-22 can go very fast far longer (because of its "supercruise" engines) than the Su-30MK, and does not depend on acrobatic maneuverability for combat superiority. High maneuverability comes in handy for a close range dogfight, but the F-22 was designed to avoid that. The F-22 is harder to detect on radar than the Su-30MK, and has a superior radar (and electronics in general) as well, which enables the F-22 to spot the enemy first, and remain undetected long enough to fire missiles.
The Su-30MK was designed for an earlier age, when the engine was the most complex and expensive component of the aircraft. Now it's electronics, and external components (that provide stealth and make the aircraft more difficult for radar to see). That's why the Su-30 is considered a 4th generation fighter, while the F-22 and F-35 are fifth generation.
The only potential Su-30MK equipped U.S. opponent is China, which has a hundred of them. Many American commander believe F-16Cs, F-15Cs or F-18s, with experienced pilots, could handle the Su-30MK. In the past, Russian fighters have always done poorly against U.S. aircraft, and the Russians have always blamed inexperienced pilots. So the big question remains, will any potential foe manage to obtain modern fighters, and well trained pilots.