The Sun from Mercury? Jupiter from one of its moons? What is the biggest object you can see on the sky standing on the surface of a solar system body? How big does it look?
Probably the Milky Way seen from any planet in the Solar System if you count that as an object. The sun as seen from Mercury is only about three times as big as it is seen from Earth.
Mars takes up 39 degrees when viewd from Phobos.
Jupiter takes up 19 degrees when viewed from Io.
Saturn takes up 36.5° as viewed from Mimas.
Uranus takes up 22° as seen from Miranda.
Neptune takes up 22° as seen from Nereid.
Pluto takes up 7° as seen from Charon.
The sun takes up 1.6° as seen from Mercury.
There might be some minor moon of Jupiter or saturn that puts all these numbers to shame, but the simulator doesn’t cover those.
[ul][]Jupiter from the surface of Metis takes up a whopping 68 degrees of the sky. [] Saturn as viewed from Pan takes up about 54 degrees of the sky. []Uranus viewed from Cordelia takes up about 62 degrees of the sky. []Neptune as viewed from Naiad takes up about 62 degrees of the sky.[/ul] Looks like Metis is the winner, at least among the named moons.
There might be another contender among the binary asteroids.
It looks to me like one component of 90 Antiope would cover 37°+ of sky when viewed from the other component.
In what way is 37 degrees bigger than 68 degrees (Jupiter from Metis)?
Just saying there’s a good possibility that there’s some double asteroid with a view matching or exceeding that from Metis. Of course, 90° is the limit, and the Metis view is getting close to that.
Um… Isn’t 180° the limit? Earth fills 143° of the ISS’ sky, but I don’t suppose there are any natural solar system bodies with orbits that low.
Yeah, it is. I plead morning stupidity.
Wouldn’t there be a practical limit for a natural object of less than 180° – specifically, whatever the visual measurement would be for an object orbiting its primary just outside Roche’s limit?
I am pretty sure the Roch limit is for fairly big and/or fragile things.
Small bodies can orbit all the way down the atmosphere/surface.
Yes, artificial satellites aren’t pulled apart by tidal forces.
Binary asteroid somewhere might be a good guess.
I’m orbiting the earth at its surface right now! And in case you’re interested, it occupies 180° of my view.
Saturn’s rings from Saturn?
If your are standing up it aint 
Awesome link and very cool that the winner was Mars and not some bigger body. Until, that is, they mentioned Jupiter from Metis. Big hog cannot leave some records for other planets.
I don’t think I was considering binary asteroids when I posted the OP but they are an interesting case.
Go to the bottom of a deep valley and you can beat that.
Or a well.
::snort::
No goatse jokes, please! 
No wonder our solar system sucks. Look how few bodies are willing to give even a 100 degrees, much less 110 degrees.
I miss that old “can do work hard” solar system I used to know.