Space elevator is by far the most efficient though . . right? Stuff that's on the end of the cable has enough angular velocity to get flung all across the inner system. Lunar orbit could be reached with release at 50,960 km. At the end of a 144,000 km cable you could get to Jupiter. I dunno what sort of other zero fuel launch techniques are getting considered though - there's no doubt a space elevator is just out of our capabilities today and for a while yet. Probably until our automation is good enough for self-directed asteroid factories to be a Thing.
The zero fuel options all sit around the same efficiency possibilities. A launch-loop won't get you as far as a GEO space elevator, but it can get farther than a non-stationary one. A sky hook can in theory get you a larger delta-v than a GEO elevator. A space fountain can do GEO, but no further...
And the very high ISP options are all on the same category in that they can save you more fuel than the zero fuel ones, but only if you want enough delta-v.
None of those are viable today, but most are in a "we can make all parts, but it's a fucking big machine that we can't assemble", while the elevator is still missing parts.
