For movies, I'd recommend
Always and
The Beast and the Beauty. Both feature a guy who is really nice and good to the girl he likes, but then sacrifices himself when circumstances lead him to believe he'll make the girl unhappy in some way... The second one is more of a comedy than the first, though ^^
For dramas, I'd recommend
Sad Love Story and
Nagareboshi.
If you want to see Guy Sacrifices Himself for His One True Love embodied in a drama, definitely check out Sad Love Story. It's a bit on the old side and a bit on the slow side for how the plot unfolds, but it fits your criteria to a tee. The male lead doesn't
stop sacrificing himself for the sake of his female lead for the entire drama; even in the last scene, that's the case.
Nagareboshi also has a slowly unfolding plot line, and a noticeable age-gap between the lead guy and the lead girl, but their story is very sweet. I'd say both the male lead and the female lead sacrifice themselves at some point for each other in the drama, which makes for an interesting watch at the very least...
