Varied, thrilling, outright gripping chart-topper (8)
I believe the answer is:
eclectic
'varied' is the definition.
(I've seen this before)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for eclectic that I've seen before include "Catholic" , "Borrowing from many styles" , "Taking ideas from various sources" , "Broad-based" , "Chosen from various sources" .)