Unreal Engine 4
The Unreal Game engine focuses more on graphics and visuals than Unity or source. That's not to say the physics are any less advanced, Unreal Engine simply makes it very easy for a game to look incredibly beautiful. Some of the more popular games that use Unreal Engine include Fable Legends, Rime, and Eve: Valkyrie, which are known for being great looking games.
image source
Unreal Engine 4's focus on graphics can be seen in the above image of Eve: Valkyrie which is a space shooter. It includes many highly detailed models of space ships, space stations, and characters which look great when proccessed by Unrel Engine. It also takes advantage of the dynamic lighting with background stars, and light emitted from lasers and laser cannons.