If you liked Half Life 2, check out Black Mesa! It’s the original Half Life game, updated with the graphics and physics engine of the second one. Pretty awesome.
You might enjoy Bioshock also.
There’s also the Splinter Cell games. I just started playing those, they’re pretty fun. They’re mostly stealth so no intense bloody violence.
Portal 2 is great, don’t know if you’ve played that one yet. It’s better than the first in my opinion.
Also if you’re a fan of Star Wars and you like RPG’s, it doesn’t get any better than Knights of the Old Republic and it’s sequel. I don’t know if you’re into either of those genres, but if you are you will definitely enjoy those games.