Mars, Venus, Jupiter and Saturn should be visible to the naked eye, but with a telescope you can spot Neptune and Uranus.

But of these planets, which is nearest to the sun? Mercury is the closest planet to the sun, followed by Venus, Earth, Mars, ...

All solar system planets have fairly circular orbits with relatively minuscule differences in their distance from the sun at aphelion and perihelion. Venus and Neptune follow the most circular orbits.