FE1/3/11/12 and FE2 have very simple plots, they lack of character development due the absense of support conversations. FE12 tried to fix that with the base conversations, but still they feel very plain.
But I like the stories on those games, simple but solid, you learn a lot of the continent and the lore.
FE4 has a complex plot; politics, lore, families, conflicts, etc.
The first part is really good, but the second part feels like something is missing. The first part explains a lot of the world they are, the friction between countries and how they try handle those problems.
Meanwhile the second part is focused in the Lopto, the Crusaders and why the war started.
In both parts you don't get to see all characters individually, most of them are there to fulfill an archetype (Like Holyn, Lynn, etc.). If you want to know more about them, you have to read the Designer's Notes, but it would be better to know that in the game rather than outside of it.
Regardless of those details, this is my favorite plot of all.
FE5 is an expansion of FE4, it explains a lot of the Lopto and how Leaf reconquered his homeland. It's not as complex as FE4, but is less confusing. You see the struggle of Leaf in detail and how he grows as a leader until the end of the quest.
I think everybody would like to see the characters of FE4 being developed as they did with Leaf.
Overall is a good story, even being just a part of a bigger story.
FE6, this story is one of the most complete of the saga, like FE4, it explains a lot of the politics and lore, and for the first time, we learn about secondary characters.
The support system was a very good improvement to the character development. Some of the things that don't explain in the main story is explained here.
But Roy is not an interesting protagonist as the others were, I can't recall something memorable of him aside from being the leader of his army. The people that were with him were more interesting, I remember a lot of Guinivere, Yodel and Elphin, I even can remember some of the things that Yahn and the others antagonists talked with Roy.
FE7 is ok, the plot is told in two points of view, and unlike Roy, Eliwood and Hector are interesting characters. You can see this in the two routes, how each handled the problems in different ways.
Again, the supports help to learn more about the story and the individual personality of the other characters.
I like this story, but it's plain and not that interesting.
FE8 takes the concept of FE7 and improves it. Not only it's an story seen from two points of view, but also they're their own separate stories.
You see how Eirika changed from a fragile princess to a independent person. With Ephraim you see the consequences of the war, how it affected people like Duessel and Selena.
But, I don't know why I found this story boring...
FE9 is other complex plot. They take their time to explain what you need to know, the division between Laguz and Beorc, the politics of each country and the current war.
Ike is a very curious character. A mercenary that doesn't care about politics, yet he gets involved in the conflict between Crimea and Daein.
I like how this story is told, it's not the noble prince that has to reconquer his homeland, is a mercenary that gets involved in the war trying to protect a person that he doesn't know is a noble.
Then the history of the nations, you get to see the point of view of almost every country, their alliances and interactions with each other, something that was rarely exposed on previous games.
I can say that this is my second favorite plot, complex yet interesting.
FE10, plotholes, Blood contract ex machina, the lack of supports...
Aside from that, it explains things from FE9 that were left unanswered and it expands the lore of the continent. The story is focused on religion and the ambition. And for the first time, you can see the point of view of two opposing armies. Then it you learn that both sides were manipulated to awake the wrath of godess.
I liked how they divided the story in parts. First the reconstruction of Daein, then the internal conflict of Crimea, the war of Begnion and the Alliance, and then the war againts the godess.
I hope one day we'll see another story developed in this way.
FE13... The first story arc was ok, but then it falls apart. They developed the story too fast. You barely learn about the continents and each country. The supports aren't as informative as in previous games, because most of them are fanservice or unnecesary comedy.
The focus of the story changes abruptly from Chrom to Robin and Lucina. Chrom is even less interesting than Roy. Lucina is well developed, but Robin... self inserts are just dull and boring. They tried to give him an appealing personality for most people, and he ended being generic and pointless.
This game tried to hard to appeal new audiences, that it lost the point of a Fire Emblem.
FE14. This is how you don't make a plot.
Why the f*ck you make two points of view and then make them pointless?
Both Nohr and Hoshido are a mess, unnecessary drama, drastic changes of personalities, useless support conversations, hollow characters...
You know nothing about each nation aside from them being in war since years ago, and that Nohr = Occidental style, and Hoshido = Oriental style.
Revelations reveals nothing, you learn nothing about Valla. If you want to learn all, you must pay the DLC.
Kamui is an inconsistent character. It changes a lot between routes to the point he can be a different character in each route.
Just because this sells, it doesn't mean that it's good. This game is filled with fanservice and anime clichés, and why? Because that sells more.
At this point they don't care about a good plot and story telling, they just want to sell.