Answer:

AMUST

AnswerCrossword Clue
AMUST"It's ..!" ("Don't miss it!")
AMUSTNot to be missed
AMUSTImperative
AMUST"...-see!" (reviewer's rave)
AMUST"It's ...!" ("Don't miss it!")
AMUST"It's ..-see!" (rave review)
AMUSTRave review snippet
AMUST"... to Avoid" (1966 hit)
AMUSTSomething that can't be missed
AMUSTSomething that's not optional
AMUST..... win situation (victory is imperative)
AMUST"It's ...-see!" (rave review)
AMUST"...-see!" (short rave review)
AMUSTSomething required
AMUSTSomething absolutely necessary
AMUSTSomething necessary