Icewind Dale, FTL, Roller Coaster Tycoon, Tropico, Pharaoh/Zeus/Caesar III, Descent, Freespace, Alpha Centauri, Age of Wonders, Commandos, Masters of Orion 2, Ground Control are some of my favorites over the years.
I had bread, I had cheese, and I had an iron. What was I supposed to do?
Anachronox Arcanum: Of Steamworks and Magick Obscura Broken Sword: Shadow of the Templars Broken Sword II: The Smoking Mirror Broken Sword 3: The Sleeping Dragon Crusader: No Regret Crusader: No Remorse Divinity II: Developer's Cut Earthworm Jim 1 & 2 Gabriel Knight: Sins of the Fathers Gabriel Knight 2: The Beast Within Gabriel Knight 3: Blood of the Sacred, Blood of the Damned I Have No Mouth And I Must Scream Jade Empire Kingpin: Life of Crime The Last Express Legacy of Kain: Blood Omen 2 Legacy of Kain: Soul Reaver Legacy of Kain: Soul Reaver 2 Outcast Phantasmagoria Planescape Torment Police Quest 1+2+3+4 Quest For Glory 1-5 Sanitarium Septerra Core Shogo: Mobile Armor Division The Temple of Elemental Evil Theme Hospital Vampire the Masquerade: Redemption
They're all worth checking out at some point.
Diners, Drive-Ins, & Dives "One embarrassing clown's quest for the ultimate case of diarrhea."
as many others have said: planescape torment, alpha centauri, ftl, divine divinity, ice wind dale series, and temple of elemental evil. i'd put ultima 7 way high up on your list if i were you, it's really a fantastic game