Yeah, Orange Box is great, and is worth a chance
You said you had it and lost it though? What you mean by that?
I completed Episode 1 and 2 rather quick though to be honest, but still rather enjoyable. I found Portal to just be amazing, and if you haven't played that, I believe everyone should. Its just such a fun experience, and the ending makes you feel great.
TF2 is fun also, but I'm not really a multiplayer fan, so get bored rather quick, probably because I'm crap at them