For moi...
Like: Unreal 3 & 4, (Gears 1-3 and Judgement looked incredible last gen, while stuff like Hellblade, Outlast II, Yoshi's Crafted World look great on Switch) Id Tech 6 (Doom 2016 and Wolfenstein II look stunning on dedicated consoles and the PC and brought mobile graphics to a new level on Switch)
Dislike: Unity (I get that it's great for making smaller scale games but I've never seen any game on it that looks especially impressive, while games using it tend to frequently have performance issues on console)
I'm not a dev myself, but my little brother is an amateur game maker and tells me Unity is easy to get the basics quickly up and running, but requires a lot of tinkering to get optimal performance, while UE4 makes it easier to create pretty graphics but its advanced features don't come cheap.
