One of Saturn's Moons, Titan was confirmed to have Lakes the size of Lake Superior except the lakes are not filled with water, they are filled with liquid ethane, methane and propane. This was confirmed by the Cassini–Huygens probe in 2004.
Below is a comparison of one large lake on Titan with Lake Superior (i.e they are about the same area). This is truly amazing. Can you imagine a lake the size of Lake Superior composed entirely of liquid methane?
Image above is compliments of NASA.gov.
The temperatures on Titan are about -290oF, so water could not be in liquid form there, but these petroleum hydrocarbons are liquid at those temperatures. Any water is permanently frozen into the rock of Titan.
Also ice has a very low vapour pressure at that temperature, so the atmosphere does not contain water vapour. Therefore on Titan, it rains liquid methane!
How alien Titan is to us, but it is still within our solar system.