The collection is great value for the money, offering lots of hours of adventure fun. Also good for those who want to start playing this from the beginning. I bought it for the 3rd one, having played the 2nd before and I must say it was quite better! Better puzzles, better linked with a better story. Great dialogs, jokes, and of course great graphics and animanted cutscenes.
Also the 3rd one has an helping guide integrated in the game (walkthrough) which is very precise when you get stuck.
It's worth to play the 2nd one before the 3rd (if not starting with the first one, as normal) because the 3rd episode kinda continues the story from the 2nd.