Mercury and Venus won’t show much besides their phases due to Mercury’s tiny angular size and low contrast, and Venus’ cloud tops obscuring its surface.
The Moon shows details mere miles across such as craterlets, ridges, and mountain peaks.
Mars only reveals significant detail when the planet is close to Earth, but for a few months out of every 26-month period Mars will reveal its polar ice caps and a few dark markings on its surface in the C9.25, along with any dust storms.
Jupiter’s Great Red Spot along with the disks and shadows of its moons are fairly easy to see with the C9.25, and the cloud belts on the planet look gorgeous too.
Saturn’s rings are quite the spectacle with the C9.25, and you should have no problem seeing the Cassini Division within them, along with cloud belts on Saturn itself. Several moons can be seen too.
Uranus is tiny and lacks any cloud details, but its disk is resolvable with the C9.25 and you may be able to spot a couple of its faint moons.
Neptune may be hard to distinguish from a star at all with the C9.25, but its only large moon, Triton, is fairly easy to see next to it.
Pluto is just barely visible as a dim, star-like point (amidst a sea of dim stars that look identical) with the C9.25 under dark skies.