No FE is bad. Some, however, are very, very old. 1, 2 and 3 just aren't playable if you're used to any standard of QoL; weirdly, I found 3 somehow less playable than 2.
I'll give 4 a 7/10. I will always prefer a black sheep that tries a lot of things, 60% of which are actually good, than a mediocre entry. Its story is not nearly as strong as it's sometimes given credit for, and its first two real maps are both fucking appalling. But I do deeply enjoy its systems.
5 is hard to place. I'll give it a 7 as well, but it... really does hate the player, and can't really be unreservedly recommended. Project Exile actually makes it fucking legible now which is mint.
I know that 7 is a better game than 6. I don't know why 7 feels so much like damp cardboard to me. It's not a bad game, and is... hilariously probably the one I've beaten the most times, around five. I'm giving both a 6.
8 decided that character writing would be a really good thing to introduce to the series. Shame it's still crippled by GBA support building. I do find it the strongest of the GBA trilogy, and an ... 8. The first game I played.
Fittingly, 9 is a 9. I'd argue it's the easiest in the series (not counting Maniac for obvious reasons), since while 8 is also fairly easy the core amount of durability every cunt has in 9 means that you're rarely closer than three bad decisions from disaster. Introduced a lot of very good systems, good story, great characters. And it's the game that introduced me to the series, which doesn't hurt.
I emulated 10 once. It ran at a constant 98% speed so the music kept cutting out. Edward got a perfect level-up and then the game crashed. I can't rate it fairly.
11 is exactly what it is and is none of what it isn't. I have the American copy because Eclipse sent it to me. 7.
12 is the only game I've ever played in Japanese. I kind of forced myself to like it for a while. I don't think it's terrible, but it's... lacking. And throwing in seventy-seven PCs was an awful decision. And dragons are bad to fight. It's just... eh. 6.
13 is the only one I've never played at minimum one map of. I'm not a grognard, you are!
14, I've only played Conquest. It's... been rough, and is just too gimmicky to really enjoy. It feels like a plate of potentially delicious pasta, but it's full of mushrooms, onions and capsicum and you have to carefully pick them out and separate them and, honestly, it still infects the taste of the rest of the pasta. Was this essentially my childhood experience with food? Constantly having things that I professed, repeatedly, that I fucking hated, thrown in or hidden so I'd be tricked into 'liking' them by my sociopathic father, until by the end of my childhood the highest praise I could possibly have for a dish is that I can just fucking lay into it without worrying about if some rubbery filthy fungus is on my fork, preparing me to try and become a capable cook myself as early as possible so I could just reliably make things I enjoy eating? I like the pair-up systems and the jug map. It's a 5.
Confession time, I was part of the wave of Olde Guard disillusioned at the direction 13/14 kind of seemed to be taking. Without having played either. Ah, good days. Anyway, 15, while slightly too faithful to the source material, reignited my love for the series. I first played it around 11pm while slav-squatting in dark athletic gear with a Nike duffel bag at a bus interchange waiting for the last wave to come out - yes, I was eventually mistaken for a thief, fairly recently at that. The maps are often bland visually but honestly they rarely suffer much in gameplay. I love the entire cast. 9.
So those are my grognard credentials and you know what, FE16 is still the best in the series, 10/10, Silver Snow pride, fucking fight me cunts.
Heroes is really good; 9.