My Top 3.
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VI had a great cast of characters, charming pixel art, possibly the best soundtrack in the franchise, a great villain, a coherent story, and some fun side quests.
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Tactics also had a great plot and cast of characters, a great soundtrack, and excellent gameplay. I could honestly make this and VI 1a and 1b.
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VII hasn't aged as well as the two previous games, but it did a lot right with some of its characters its world building, its gameplay, and its side quests.
Edit: Honorable mention is IX, which I think would edge VII out for the third slot in my Top 3 if half its playable characters weren't largely irrelevant.