What games engines could handle my computer as decently as the Source engine

I just want to know because I tryed another game on another engine and it either had too much graphics or watever, anyways know any other games with different engines that have much power as the source engine and graphics like half life or maybe a little bit higher and has multiplayer

It would probably help if you posted your specs.

The source engine is probably one of the best optimized engines you'll ever play on.