Whatever you think of the 360, though, there's no denying that, in the long run, it will be the system people think of as defining this particular generation of home consoles.
The PS3 is the powerhouse that will last longer as far as viability in the market, but due to poor opening numbers, the sorry online service (from what I've heard,) and issues with backwards compatibility it has never been able to fully make up for its early-run lag behind the 360 and Wii. Sony has made a profit on it, and it really does well in proving their proclaimed business model of running a system on a ten-year or more cycle as being not only possible, but extremely well-thought. In the long run, though, its lack of market saturation and many truly generation-defining games drops it from the top.
The Wii... while it opened strong, and sells well, the ungodly amount of shovelware and Nintendo's vastly overinflated software prices (most of their first-party titles from launch still cost upward of thirty bucks to buy new) on anything worth buying hurt it even worse than its weak graphics processing and gimmicky control scheme. Just because the 360 and PS3 have both integrated motion-control setups into their systems doesn't do anything to lower the gimmick-value of it in the long run, and while I can see it being an option for some time to come, I don't see classic SOYA (Sit On Your Ass) controls disappearing any time soon.
Then there's the 360. As much as it pains me to say it, the 360 entered the market at the right time with the right numbers and the right hype to pull in the sales. RROD issues hurt it in some people's eyes, but it managed to overcome those fairly well, and with proper care most issues can be largely avoided. It has had a steady price drop since inception, with a variety of models appealing to different demographics, and excellent second- and third-party development support. Everyone complains about the limitations placed on computer games at the moment? Moreso than the PS3, the 360 is to blame, and that should be even more proof of the long-term effects the system will have on the market.
The 6-bit era had Atari, the 8-bit era the NES, the 16-bit era arguably the Genesis, 32-bit was the PlayStation, and last generation was the PS2 (though I wish it had been the Dreamcast so hard.) Facing the facts, when people look back on the current generation, the first thing that's going to pop into their heads will be that funky-shaped rectangle with the glowing power sign on the front., whether it be red, green, or any other color of the rainbow.
(rant over)