Matthew Fox cried many a time on 'Lost'. Here is a subtle moment near the end of the first season, as Josh Holloway (Sawyer) tells him (Jack) about encountering Jack's late father. I love how Jack turns away as soon as he realizes where Sawyer is going with his story, and how Sawyer, normally a scoundrel, looks at Jack without flinching and chooses to share the story.

https://www.youtube.com/watch?v=45If9L0MxDI