REMAKE EVERY LAST ONE OF THEM!
... jokes aside, every game so far can really benefit from a remake,
ike's games both have some VERY glaring flaws, and awakening needs a combat rework as well as more narrative.
The GBA games are the ones that least need a remake actually.
we STILL haven't gotten an incarnation of FE3 yet in english, and Shadow dragon was trash gameplay wise so there is that.