Here is a list of some amazing CSS parallax effects examples.
Page top parallax
Dev: jakob-e
Parallax Grid
Dev: Casey Callis
Parallax Background
Dev: Ravi Dhiman
CSS Only parallax
Dev: Sil van Diepen
CSS Parallax
Dev: Alex Martinez
Background image scrolling effect
Dev: Jeff Mills
Magdiellop 216 recreated with CSS
Dev: Guilmain Dorian
Mouse Move Parallax
Dev: oscicen
CSS Parallax Effect
Dev: Braydan Willrath
CSS Parallax Effect (3 Layers)
Dev: medienmarmela.de
Whole UI without javascript | on pure css
Dev: Andrej Sharapov
CSS Sticky Parallax Sections
Dev: Ryan Mulligan
Pure CSS Parallax
Dev: Jordan
CSS Parallax Effect
Dev: Jesus Rodriguez
Pure Css Parallax Effect using single Div
Dev: ezaz
Pure CSS Parallax Effect Demo (with content)
Dev: FlyC
Parallax without js
Dev: Ahmed Essa
Simple CSS Parallax Effect
Dev: Hornebom
Pure CSS Parallax Effect (Depth of field)
Dev: FlyC