Quoting awilbohk:

Quote:
I know most would say: take the most listed. 

Luckily, we're not after the most-listed name variant, but the most-credited one. The number of profiles you've quoted is of no importance whatsoever - it's the number of actual different titles we're after. Based on the CLT the common name is Henry Lloyd Hughes (no hyphen), with credits in 'Harry Potter and the Goblet of Fire', three series of 'The Inbetweeners' and 'Telstar: The Joe Meek Story'. Henry Lloyd-Hughes (with hyphen) only seems to be credited in one episode of 'Murphy's Law', and three incorrect, IMDb-mined 'Harry Potter' profiles that shouldn't be taken into account. So the common name is Henry Lloyd Hughes (no hyphen).

Moving on to the second part of your question: the parsing. That's not decided by the CLT, nor by how many profiles use a particular variant. Instead, we aim to parse "correct", although it's usually near-impossible to determine what that is. With the backup you've provided, however, it seems to be clear that both "Lloyd" and "Hughes" are part of his last name. So while how he's mostly credited ensures that we can't use the hyphen in his common name, we can parse his name correctly. As such, I would say that for our purposes, his common name should be entered as Henry//Lloyd Hughes.

Henry Lloyd Hughes - 1 confirmed
Harry Potter and the Goblet of Fire (confirmed by me)
Telstar

Henry Lloyd-Hughes - 8 confirmed
Anna Karenina (confirmed by me)
Anonymous (confirmed by me)
A Fantastic Fear of Everything (confirmed by me)
The Inbetweeners: Series 1, Eps 1 - 6 (confirmed by me)
The Inbetweeners: Series 2, Eps 1 & 3 (confirmed by me)
The Inbetweeners: Series 3, Ep 2 (confirmed by me)
The Inbetweeners Movie (confirmed by me)
Murphy's Law: Series 2, Ep 5 (confirmed by me)
Weekender

Quoting emmeli:

Quote:
Sex on the Beach: Henry Lloyd-Hughes

That's just the German title for "The Inbetweeners Movie".