In my vocabulary, sick is a word with several meanings.
Sick, as in "I am so sick," literally suffering from an illness.
Sick, as in "That food was so sick," meaning really gross.
(Add 'nasty' for emphasis if necessary)
Sick, as in "That Ke$ha concert was sick," meaning totally awesome.
(Add 'money' for emphasis)
Just wanted to share that little gem with the world.