I'm looking for game suggestions preferably RPGs and any games with a marriage/generations system like what phantasy star 3 had

Upon mentioning marriage/generations Agarest games come to mind instantly.

While not available on this site, there are a couple Super Famicom games that have something like this, namely Dragon Quest 5 and Romancing SaGa 2.

Note, however:
* I actually consider Dragon Quest 5 to be one of the weaker games in the series for various reasons. (The remakes fixed *some* of it, like the fact that party size is limited to 3 (not 4 as in other DQ games), but not all.)
* I have not played Romancing SaGa 2, and from what I know about it, it might not be your best entry into the series. (I would start with 3 (which I haven't played) or the PS2 remake of 1 (which I have played) instead.) I don't think this game has marriage, however, but it does have generations.
* SaGa Frontier 2 (PS1) doesn't have a marriage option per say, but it still covers a long period of time (86 years), and the main character on the Wil Knights side of the story (that is, Will Knights himself) actually has a grandchild who takes charge of the late-game party. Beware, however, that this game is notorious for its hard final boss, and you can't leave the final dungeon when you enter (this restriction is common for dungeons in this game, but the final boss's hard difficulty isn't). (There's one other part that's notoriously difficult, but it's not actually required (unless you want to see what I consider to be the ending of Gustave's story).)

As for games available here, while it's not an RPG and doesn't have marriage, Rogue Legacy does have generations.