These are my favorites!
Titanic: Adventure Out of Time
Broken Sword 1: Shadow of the Templers
Broken Sword 2: The Smoking Mirror
Broken Sword 3: The Sleeping Dragon
Gabriel Knight: Sins of the Father
GK2: The Beast Within
GK3: Blood of the Sacred, Blood of the Damned
The Longest Journey
The Curse of Monkey Island
Monty Python: In Search of the Holy Grail
Shiver 2: Harvest of Souls
With all the great sounding games due out this year, this list may be different next year!