There is a lot of great hack around, and a lot more that I still haven’t tried, but I really like Dark Lord and the Maiden of Light ! It felt so much like a gba fire emblem that I would have played when I was a kid ! There is also some very clever ideas of level design, that blown my mind ! The only things that I’m less fan about the hack is the endgame, because the spike of difficulty is very sharp compared to the rest of the game 
But like other said, I’m always very impressed by The Last Promise, Blazer was a teenager in a times with few hacking tools and he delivered something very solid in terms of game design ! Also, I have a soft spot for Sun God’s Wrath, when I come back to romhacking (after trying TLP and Elibean’ Night years before) it was the first hack I tried and, with the overflow of contents it has, I was like “Wow FE romhacking really get very far since last time I checked” 