Which series do you feel captured the spirit of the '00s best? As in, clothes, hair, technology, everyday life, social issues, the way people behave etc?
For me, it's a close tie between Desperate Housewives and Grey's Anatomy.
Well the decade was not all the same and things changed.
I'd say for the early part of the decade--post-9/11, War on Terror paranoia, Bush-era dominance--is reflected in all its ugliness in 24.
I think a show that captured the style and attitude of the middle part of the decade (some would say its shallowness) was Entourage. That I guess can include the way people communicated with new technology.
Youth culture itself and its quest for fame can be embodied in a multitude of shows. The reality show glut best represented from the attention-craved longings of American Idol to the complete uselessness of Jersey Shore or the early cynicism of Glee when it started as a satire of the way this generation thinks/acts (though it has become a dumbed down top 40 commercial after the first season).
Both Glee and Modern Family are tapping into the changing attitudes about the LGBT community in the mainstream. Compare those shows to the condescending tone of Will and Grace just ten years prior.
There are different parts of our culture that different shows captured.