AMD is better with programs and games that use multiple cores as the cores themselves are simply a lot weaker than what is supplied in a Intel CPU.
Games for the most part never use more than 4 cores with only a handful of them even using that. Unless that game is heavily optimized for more cores than that then the Intel chipsets Is always going to out perform AMD and even then the fact that the Intel chips are so much more powerful core wise the difference still isn't that big a difference.
Also factor in that 90 percent of the CPU's in machines capable of running a high end game is using Intel so obviously developers are going to spend more time optimizing for those systems.
AMD is great for the value they offer and for someone who doesn't have tons of money to spend I always recommend AMD products.
With the inclusion of the New Consoles being released here shortly we may see a lot of game lean towards AMD with a higher performance margin between the 2 chip makers.