... you've impressed me enough to see if you can get these, even though they're not movies - these were either in a 1980s series on PBS or were one-shot film shorts for kids:
1. a boy meets a girl on the bus whose family doesn't own a TV; kids make fun of her but the boy decides to be her friend anyway.
2. in a world where it rains everyday, a kid gets locked in a closet during the only sunny-day of the year and doesn't get out until it starts raining again. All the other kids get to play in the sun.

The second one is All Summer in a Day (1982) (TV) (http://www.imdb.com/title/tt0195517/). Don't know the first off the top of my head, but I'll get back to you if I can find it.

First one has to be Bridge to Terabithia. There was a 1985 TV movie.

Your second one sounds like a short story by ray bradbury... a very sad story actually

The TV show to the second one you mentioned is called "wonderworks" and the Ray Bradbury short story is called "All summer in a day"