Capitalism. Not only because there hasn't been a model of socialism that isn't a utopia, but also because capitalism is functioning well for many. Aspects of both are needed for the perfect world, but in our world today I am happy with capitalism.
Wikipedia defines "utopia" as "an imagined community or society that possesses highly desirable or nearly perfect qualities for its citizens." Isn't that actually a good thing? I guess the problem is that it seems we haven't been able to implement one of those perfect imagined communities in real life yet.
I think capitalism is always great for the people on top. The rich get richer, as they saw. I do think though, in a society with limited amounts of corruption, there is always opportunity. I think that no matter what your origins are, in capitalism, you can always go up if you go about it smartly.