It’s kinda funny that, according to the novel, he’s supposed to be 25 years old
But there will only ever be David Bamber’s Mr Collins to me (although I did kinda enjoy Lost in Austen).

David Bamber was great, both ladies AND gentlemen will run at his Mr. Collins

Just as for me Colin Firth will always be THE Mr Darcy.
Fun fact the fountain scene in Lost in Austen was a copy of the lake swim scene of Mr Darcy in P&P 1995. There is no such scene in the book.