TheNamelessOne_PL: So I was wondering. There are obviously many great games on GOG. But which one is the most iconic? Which one is so iconic that you can't help but smile whenever you think about it?
You are making the wrong assumption that an iconic game would make people smile. A game can be iconic, but you don't need to like it at all. On the other hand, if you are asking about favourite games, even the worst games are someone's favourites for some reason.
But if you want a specific product, let's say Leisure Suit Larry collection.
It's a good piece of gaming history, those are Good Old Games, it's from Sierra which was the biggest software house at one point in time, it has parser-driven games and point-and-click games, both of which were the most popular genre in their own time for a short while, and they come from a time when games were simply fun without any concerns about being politically (or otherwise) correct.
I suppose you could consider some Ultima collection or something like that too, but I think LSL is a better choice. If the original Monkey Island games were available here, it would be an easy and obvious choice, but as they are not... well... not happening then.