-Uranus (the 7th planet) was discovered over a hundred years after Neptune (the 8th planet). It had been sighted many times, but was mistaken for a star.
-It is the last planet visable with the naked eye.
-It orbits on it's side, like Pluto. (Though, props to Venus for being what I would consider upside down.)
-It rotates in retrograde, like Venus and Pluto.
-It has 13 rings which are oddly dark, most likely because they're composed of carbon and ice.
-It's magnetic field is very strange. Not only is it tilted so that it's closer to the equator than the axis, but it doesn't even run through the center of the planet. Being of a similar make up, Neptune also possesses this strange magnetic field.
-It has 27 moons (including Miranda, which has a feature known as Verona Rupes. This is a cliff that is 12 miles high and is known as the tallest cliff in the solar system. To put it in perspective the Grand Canyon is only a mile deep.)
-Many of the moons are named after Shakespearean characters instead of mythological characters. There are also a few named after characters created by Alexander Pope.
-In H. P. Lovecraft's Cthulhu Mythos, Uranus is known as L'gy'hx and is inhabited by cubical metallic many-legged creatures who worship Lrogg whose rituals require a yearly sacrifice in the form of the excising of the legs from a native. (Who doesn't love mythological leg-eating creatures?)
Here are some short videos on Uranus. I recommend the one about the magnetic field.
[Edit: Neptune was first observed in 1612, but it wasn't discovered (as a planet) until 1846...meaning that while it was observed before Uranus (1690), Uranus was correctly identified as a planet (1781) before Neptune...meaning that I'm on crack. My bad. Thanks to smailtronic for pointing out my mistake.]