The animes that had OSTs that left the biggest impact on me are listed below. (OVAs, second seasons, etc.'s OSTs will be counted as part of the first/original season.)
List of Anime that have made me cry. (From once or twice to 11306067864563452648 times.) Ranked in order from the ones that made me cry the most to the ones where only a couple of tears were shed.
Ranking of all the Romance anime I've seen so far. (OVAs, specials, etc. of TV series will not be included.) I've included some anime that aren't tagged under "romance" that I feel should be.
Every person who watches anime should see these.