Answer:

extremes

Answer	Crossword Clue
EXTREMES	They're poles apart
EXTREMES	Go to ... (be immoderate)
EXTREMES	The sublime and the ridiculous, for instance.

EXTREMES	Outer limits.
EXTREMES	Utmost lengths
EXTREMES	What radicals go to
EXTREMES	Go to ... (overdo)
EXTREMES	What dare-devils go to
EXTREMES	Guinness data
EXTREMES	They're polar
EXTREMES	People sometimes go to them

EXTREMES	Drastic measures
EXTREMES	What the desperate may go to
EXTREMES	Polar opposites
EXTREMES	Opposite poles
EXTREMES	Billy Joel's I Go To ....
EXTREMES	Range's boundaries
EXTREMES	What overdoers go to