nothing's rotten in Denmark

Trivia question:  What play is the sentence "Something is rotten in the state of Denmark" from?

There apparently isn't much rotten in Denmark these days, as it turns out.  Jon forwarded to me the list of the ten happiest countries in the world, "happy" being based on responses to how satisfied people are with their present life and their predicted satisfaction with their future life, per Forbes magazine.  The happy countries:
1)  Denmark.
2)  Finland.
3)  Netherlands.
4)  Sweden.
5)  Ireland.
6)  Canada.
7)  Switzerland.
8)  New Zealand.
9)  Norway.
10)  Belgium.
(If you go back to my blog post on 8/18/10, you will  find Newsweek's list of the "best countries in the world", and the list isn't much different!).

Jon's comments:  "Be sure to point out that none of them are the US, and 8 of the 10 are in that horrible continent that has ruined itself with socialism" (-- more reasons to be proud of my left-leaning son!).  :-)
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Trivia answer:  The quote is from Shakespeare's Hamlet.