With Fire Emblem we all had our first game. And I would not say all but many of us had their first crush in Fire Emblem. May it be the first unit which granted you success and did very good on the first playthrough. the writing about the character or the design.
So I will start with mine. Unlikely to what characters I am boasting around now it was Guy from Blazing Blade.
Guy was the first Fire Emblem character I truly liked and I still remember after all those years with Blazing Blade as my first Fire Emblem game he was a unit I had a lot of fun with. At those times I greatly preferred to use Myrmidons. I liked quick characters with a good Dodge rate and the Special animation they had was engraved. With Guy as one of my first units to fulfill that he has quite some place. Additionally I really liked his design, a guy with long green hair and a quick swordfighter? I was down with it.
Sometimes taste in characters changes and you are getting to like other characters more, or they still have a special place in you. So for this thread it's nice to just remember what you liked first. But still I remember that he was the first character which I had taken a liking to and took great care of in my first playthrough.