I've been playing fire emblem for 15 years, although i haven't played many games in the series. My favorite is PoR, and I also played Blazing Blade which i enjoyed. I prefer PoR for its better story (I remember almost nothing about FE7's plot except the main characters and taking place in Elibe). I have Three Houses which I bought for my dad because he loved PoR but he didn't seem to like it as much because of all the non-combat stuff they ask you to do in the game.
Favorite character is Jill because she is busted in-game and also has arguably the best story of all the side-characters.
Favorite from FE7 is Florina because she was absolutely busted in my run:
I'm doing a run of FE9 right now on Normal. Still as fun as ever but very slow-paced, takes an hour on average per chapter or more. I have a copy of FE10 but it can't seem to load the fighter class properly, so it crashes whenever a fighter tries to go through a class change. I want to play through it eventually but we'll see. I'll probably play through Three Houses plus the GBA games which I started but never finished.