Allow me to recommend a bundle of four adventure games (fifth is allegedly in the making) that are, in my opinion, near perfect as far as adventure games go.
They look very humble, especially the first and second game, 90s style hand drawn graphics, low res art. However, the writing is IMO excellent, the characters interesting (I did care about what happens to them), with clever references across the episodes. They are heavily story-centered, which is IMO how adventure games should be. The puzzles are rather easy and scarce, the main focus is always the dialogue. However, you won't find any cliche item-based recycled puzzles I hate so much here, no more carrying odd sticks, nails, rusty cans and stones to use them in the most unprobable and impractical manner.
The theme is very simple and not very original admittedly (Randall and Hopkirk, anyone?), but the pacing and the immersion is superb.
The games themselves are rather short, I finished the four of them in five evenings (the fourth one is longer and much more tricky), but I did not have to use a walkthrough at any point.
I am looking forward to the next iteration that should be out this fall.
Highly recommended for all bookish adventure fans with a soft spot for Marlowesque noir style with a dash of occult and supernatural.