The most common and most likely answer to this crossword clue is the 4 plus 4 letter word HIGH SPOT
I've seen this crossword clue in The Sunday Telegraph
H
I
G
H
S
P
O
T
More clues leading to the result HIGH SPOT
- Best bit of acrobat’s performance?
- Most memorable experience could be Helvellyn
- Outstanding moment, greeting said spy
- Perhaps Snowdon’s most memorable part?
- Euphoric experiences with marijuana — a most memorable thing!
- Best thing about goth’s hip getting broken
- On a trip, identify most memorable moment
- Intoxicated, drunk with power for thrilling moment
- Most memorable part of euphoric states on marijuana
Buddy explains!

The straight part
We know that "Outstanding moment" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case outstanding moment = high spot.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.