Is Earth's 1g solid surface gravity unusually high for exoplanets? The surface gravities of the Sun’s planets are all close to 1g, 0.38-2.53 (about a factor of e, by chance). The cloud-top gravity of the gas giants is not too interesting here, but I suppose that the gravity on their solid surfaces (if any) does not tend to be higher. So called super-Earth exoplanets seem likely to generally accumulate light gas atmospheres, which decreases their expected solid surface gravity relative to their size as measured during for example transits (I suppose so anyway).

Are there good reasons to expect that in the zoo of planets in the universe, our Earth scores high in the surface gravity top-list? That it is unusual with solid real estate to stand on which has substantially (as in a factor of a few tenths) greater gravity than we have here?

Surface gravities from Wikipedia:


Mercury  0.38
Venus    0.90
Earth    1.00
Mars     0.38
Jupiter  2.53
Saturn   1.07
Uranus   0.89
Neptune  1.14
According to this paper, fig. 4, solid planets of arbitrary mass (up to 3,000 times Earth's mass) don't grow much about three- or four-times the Earth in diameter. That's because interior parts of the planet become compressed by the high pressure. Planets heavier than 3,000 times Earth's mass are in the transition zone to stars. In the case of rocky planets they would become substellar objects, similar in their physical properties (electron degeneracy in the core) to white or black dwarfs, not capable to start nuclear fusion due to lack of light elements in their core.

Surface gravity is proportioal to the mean density $\rho$, and to the radius $r$ of the planet: $g=\frac{4\pi}{3}G\rho r$, with $G$ the gravitational constant.

A planet with roughly the composition of Earth, and 3,000 times the mass of Earth would have about 3-times the Earth's radius, hence the 27-fold volume, and the 3000/27 = 111-fold density. Its surface gravity would hence be 333 g. That's close to the upper bound of surface gravity of what would be called a planet. With a pure iron planet we could go a little beyond. Any surface gravity below this upper bound is possible for a solid planet, at least in theory.

According to page 1284 of the paper:


  Massive solid exoplanets of
  hundreds to thousands of Earth masses may be able to form around
  massive stars (B and O stars; 5-120 solar masses) where the protoplanetary
  disk would contain enough heavy elements.


B and O type stars are rare (0.13% of main sequence stars) and short-lived (less than 100 million years; more accurately less than $10^{10}\cdot 18^{-2.5}$ years, for mass > 18 solar masses). Hence large solid planets of the described type will also be rare, although a priori not impossible.

The planet with the highest estimated surface gravity discovered thus far (March 8, 2014) is
CoRoT-Exo-3b (add "surface gravity" column to the exoplanets table, and sort by that column):


  CoRoT-Exo-3b has a radius of 1.01 ± 0.07 R_Jup and transits around its F3-type primary every 4.26 days in a synchronous orbit. Its mass of 21.66 ± 1.0 M_Jup, density of 26.4 ± 5.6 g cm-3, and surface gravity of logg = 4.72 clearly distinguish it from the regular close-in planet population, making it the most intriguing transiting substellar object discovered so far.


A surface gravity of logg = 4.72 means surface gravity equals $10^{4.72}\mbox{ cm}/\mbox{s}^2=52,480 \mbox{ cm}/\mbox{s}^2 = 53.5~g.$ 
This research has made use of the Exoplanet Orbit Database
and the Exoplanet Data Explorer at exoplanets.org.

CoRoT-3b on Wikipedia.