No one has said ‘Maniac Mansion’ or ‘Zak McKracen and the Alien Mindbenders’. Two of the first in the genre yet absolute classics that still play well today.
Others worth looking into:
-Monkey Island (I and II. The later ones were okay but didn’t hold the same magic).
-Thimbleweed Park (relatively new and phone ready).
-Beneath a Steel Sky (a little dated now and hard, but worth persevering with)
-Legend of Kyrandia (1. I never tried the second, but the first held a special magic back in the day).
-Simon the Sorcerer
-Flight of the Amazon Queen
-Grim Fandango
-Indiana Jones and the Last Crusade (Still holds up as a great game)
-Indiana Jones and the Fate of Atlantis (Like a new Indy movie!)