A good engine is the engine that helps you develop games the best.
So what you are looking at is an engine that is:
- Easy to learn
- No bugs that needs to be worked around, you don't want the engine to create a net positive work for you to do
- Reduces the amount of work you need to do
- Supports the game you want to do
- Playable test version of the game as soon as possible
- Re-usable gameplay components that you can just plug into your game (player characters, damage system, ability system, AI, navigation etc)
The first step would be to decide what kind of game you want to do and what gameplay mechanics it needs to have. Then you need to compare your game needs to what each individual engine offers and see how good of a match it is.
I use Unreal because once you get over the learning curve, it is easy to use and I can develop games fast using it. It comes with a powerful character class already which means setup up your protagonist movements can be done in minutes and you'll be walking around in your test level within 15 minutes. Assuming you want to make a game with a single humanoid player character that is.