normal rope

• constrictor knot
  Easy to tie (a minor variation of the clove hitch), and strong as hell.
• bowline
  The queen of knots. This is the pinnacle of civilization right here.
  (the bowline on a bight is still more clever, and simpler to adjust)
• buntline hitch
  Like the round-turn-and-two-half-hitches, but much more secure.

webbing

• water knot
  It may be an obvious standout, being the only knot that's specific to webbing. But it's one to remember.

fishing line

• perfection loop
  The bowline of fishing line.
  (my preferred method of tying)