Except for Mercury, the planets in the Solar System have very
small eccentricities.
Is this property special to the Solar System? Wikipedia
states:
Most exoplanets with orbital periods of 20 days or less have
near-circular orbits of very low eccentricity. That is believed to
be due to tidal circularization, an effect in which the
gravitational interaction between two bodies gradually reduces
their orbital eccentricity. By contrast, most known exoplanets with
longer orbital periods have quite eccentric orbits. (As of July...