Microsoft has made great strides this generation and change the way console games will be played from here on out (Live and Achievements). But they're just not on the same level as Sony yet. I prefer the 360 over the PS3 as well, but the PS2 continues to sell 10 years later and Microsoft has not released a competitor in the handheld market yet either. The original Xbox was shelved 5 years after it's birth (I know they didn't have a choice), and outside of NA, the Playstation name is still a stronger seller.
I also don't think its fair to compare the 360 to just the PS3 when your talking about gaming brands. It would be like discarding everything Nintendo did before they released the Gamecube and calling them a failure because the PS2 outsold it dramatically. Meanwhile, the GBA was flying off the shelves.
