Ok so here's all of the grinds I could think of, I'm sure there's some obscure ones I missed though so please someone list those too.
Peg grinds:
Feeble
Smith
Double Peg
Icepick
Toothpick
Pegless grinds:
Feeble
Smith
5050
5-0
Overcrook
Nosebluntslide
Boardslide
Lipslide
Variations of grinds:
One-footed grinds
Hurricane grinds (most commonly seen with feeble grinds and boardslides, but are also possible with smith grinds, lipslides, and overcrooks--though no one has done an overcrook hurricane yet.)
FSF and SF grinds (such as FSF boardslides as done by BenJ Friant and those weird FSF grinds done by Jon Reyes)
Fakie grinds
Edit: Underside grinds (as seen with Terry Price's underside toothpicks, but not limited to peg grinds)