Although I've never lubed a Rubik's Cube before, but I suggest a dry lubricant, such as graphite.

Check out this website for Rubik's Cube lube http://www.rubikssolver.com/Rubiks_Cube_Store.html

I've used vasaline. In order to do this, have it solved, and take out all the pieces and..ya know, lube it up. Then put back all the pieces. Voila.

KY Jelly? Hang on, what do you mean "lube your cube"??

WD40

use silicone spray at frist it will make the cube hard to spin but after a day solving it it sould be good to go but if u use it on an old cuase that has been used alot it sould be able to go rite away just work it in but sloveing it a few times,but DON'T use WD40 that stuff will slow it down,also anther thing that will work is cooking oil but u need to take the who cube apart whitch takes some time to put back togather and it will only last a day but it u want to do it that way be my guest

I use Cooking Oil, you dont need to take the whole cube apart, just one piece, put a couple drops of it inside, and rub a but on the sides of the cube part you took out, play with it a little, rub off the extra, and repeat a couple times... works wonders for me, i couldnt move my cube at all with one finger, now i can move it all the way around faster than i can blink O_O

OK I have original Hungarian cubes that I bought in Germany in the 80s and lubed with vaseline - they're still fine. But vaseline is gunky, thick, and attracts dirt; so I switched to silicone. The ingredient you want is Silicone Oil, or Siloxane - CAS# 63148-62-9. CAS stands for Chemical Abstracts Service and every known chemical - including water - has a registered CAS#. No matter the brand - CRC, Pyroil, GE... - silicone sprays are about 80% Heptane but only 8% silicone. Heptane is also known as white-gas, Coleman fuel, or zero-octane gasoline. I wouldn't put gasoline on any of my cubes. And since the aerosol propellant is usually propane, silicone sprays are EXTREMELY flammable! Isn't it nice to know that a 10oz can of silicone spray contains 8oz of gasoline but less than an ounce of silicone? If you use a spray - just do one short squirt at a time and make sure your cube is completely dry before putting it down. I use a water-based silicone protectant like ArmorAll Original Protectant or STP son-of-a gun. They contain 15-20% silicone in a water-based emulsion, and sometimes a little bit of UV blocker. I apply lightly to the inside of the cube with a #4 artist's brush. It's good, it's cheap, it's meant for plastics, it won't fuse your cube, it won't blow up your house. I don't use Jig-a-loo because the mfr won't disclose the ingredients - even generically, and I have reason to believe it also contains petroleum solvents that will harm your cube. Some people have used too much on their DIYs and turned them into solid blocks of plastic that only look like a cube. If you're not sure about a product, look up its MSDS - material safety data sheet - online...WaW...