What type of grease to prevent seat post sticking? What type of grease should I buy specifically to prevent the seat post from getting stuck in the seat tube? I believe its aluminum.  Is there all-purpose grease that I can use for other parts of the bike?  This is an older, inexpensive bike that I need to last for another few years.
I use basic thick grease from an auto parts store. The can says multi-purpose waterproof grease. It's thick like a cream, or butter and dirt cheap. You only need a small amount.