I like adventures but usually I get stuck in the ones that have really difficult puzzles or where to go is too obscure. I welcome any recommendations but I also have a few that I wonder about specifically that look interesting: Gabriel Knight 1, The Last Express, and Sanitarium.

Loom!

Should hopefully be here soon. ;)

You can die in Sierra games, some consider it hard beyond unfair.
Gabriel Knight is a great combination of puzzles and talking, but it's a bit more complex, compared to the standards of LucasArts adventures, that are fairly easy.

Full Throttle. It´s easy and fun, but sadly not available on GOG.

The Longest Journey.

Agree with this one

And Dreamfall too ... (though there's a bit of combat in that one)

Of course... Using Zoë as an avatar...

Yep, avoiding Sierra now, though Police Quest seems kind of interesting.

Yeah start out with this one.

I never got to play that or Grim Fandango, would love to someday. Day of the Tentacle was great.

That one is especially hard, sometimes it's book a guy by the book or game over.
Now, i may be weird, but i consider Sierra adventure games as the pinnacle of the genre, when games were entertainment that required a lot from the player. And the death scenes in some were hilarious. Anyhow, if You save OFTEN and play it wisely, not just clicking on everything, You might just enjoy it. And PQ has a neat story.

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Buuut i'd leave it for a day when You find a need for something hard [no pun intended].

Dreamfall was good, played that on the Xbox.

I thought The Longest Journey here on GOG was Dreamfall: The Longest Journey, will take a close look now.

Sanitarium is brilliant, but it is kind of unstable without making some adjustments. The subforum on it gives more details, but I don't think it plays well with multicore computers without its affinity being set.

The other main problem with it is that it's really short. I played through it my first time from start to finish in a weekend. Granted that was all I did that weekend, but it is both short and addictive.