The Fellowship Of The. Ring - Frodo and Sam beginning their lonely trek into Mordor.
The Omega Man - Maybe not the final shot exactly (It's been a while), but
has always been a memorable shot for me.
The Incredible Shrinking Man - Scott resigning himself to his fate. Another Richard Matheson adaptation, as it happens.
That is pretty much the final shot of The Omega man, very biblical!
I love the ending of the Haunting (1963 version) but then I love every moment of it.
And the end of On Her Majesty's Secret Service is pretty darn powerful as well.