The Peano curve is a space-filling curve.
The Hilbert curve is also a space-filling curve.
The Moore curve is very similar to the Hilbert curve, but it can be looped.
The square space-filling tree is not a space-filling curve; it's a space-filling tree.
The arrowhead curve would be a space-filling curve... if space was a Sierpinski triangle.
The Gosper curve is a pretty cool space-filling curve, if you're into that sort of thing.