Myst & More is a bundle of Cyan games for $11. Some early games. All of Myst which is the series that made them famous. And Obduction which is their last original release so far.

Myst: Masterpiece Edition ($6, Owned on GOG) - recreates the first Myst with re-rendered images and UI improvements
realMyst: Masterpiece Edition ($18) - a version of the first Myst but done with an FPS engine

Riven: The Sequel to Myst ($6, Owned on GOG)
Myst III: Exile ($15)
URU: Complete Chronicles ($10) - I guess set in the same universe but not part of the main plot
Myst IV: Revelation ($15, 32-bit)
Myst V: End of Ages ($10, 32-bit)

Obduction ($30, Owned on Epic+GOG) - Myst-like experience in a totally new universe

The Manhole: Masterpiece Edition ($6, Windows) - point-and-click adventure
Spelunx and the Caves of Mr Seudo ($6, Windows) - point-and-click adventure
Cosmic Osmo and the Worlds Beyond the Mackerel ($6, Windows) - point-and-click B&W adventure

I guess it's Myst III and URU as everything else is a remake, I own, or can't play. Actually this is a bundle I can skip.