I have a weird play order so I'll mention this first. FE10 when it came out, then 13, 3H, 4, 5, 9 and 10 again
FE4 - Incredible story gameplay integration, great unit characterization (best in the series?), fun gameplay that is surprisingly streamlined. No outstanding flaw that contradicts the core design ideas behind this game : 9/10
FE5- A game of extremes. Amazing atmosphere, some incredible maps, lots of mechanics to play with, BUT dreadful first time experience, underdeveloped characters (looking at you Asbel), too much variance for my taste, a handful of really bad chapters : 7/10 (6 if you just want a consistent, single playthrough, 8 if you really like investing time/thought into a game)
FE9 - The most consistent and honest FE experience. Everything is good, but sadly having played it for the first time in 2020 nothing feels outstanding in retrospect : 7/10
FE10 - Beautiful presentation and some interesting mechanics but it just always bores me. I can't get myself to play it. First time experience is also really bad because it's impossible to know what's worth investing in. I disagree the map design is particularly good compared to other things I've seen in the series - 5/10
FE13 - I have to give it credit for being the first game to really get me into the series. Looking back, it's an outstanding role play experience but a bad TRPG - 7/10 (a lot less if you want a TRPG, more if you like roleplay and you like to plan your characters ahead)
FE3H - A game of contradictions. Designed to be replayed but full of tedious stuff you never want to do it more than once. Marketed on its characters but they are too customizable to feel different enough. Still a massive amount of fun on a first play through and a good entry point in the series. A lot of fun role play and planing opportunities too : 7/10
Conclusion: too many 7/10. I feel a lot of these games do a couple of things really well and a couple really poorly.