Go for the best (6)
I believe the answer is:
select
I believe this clue is a double definition.
'go for' is the first definition.
(I've seen this in another clue)
'the best' is the second definition.
(I've seen this before)
(Other definitions for select that I've seen before include "'Choose, pick out (6)'" , "Choose from several" , "Choose, being special" , "Exclusive - choice" , "Choose, decide" .)