Unpopular drama is best (7)
I believe the answer is:
outplay
'is best' is the definition.
'unpopular drama' is the wordplay.
'unpopular' becomes 'out' (similar in meaning).
'drama' becomes 'play' (synonyms).
'out'+'play'='OUTPLAY'
(Other definitions for outplay that I've seen before include "Act better" , "Defeat (sport)" , "As sportsperson, overcome" , "Excel at games" , "Perform better than" .)