From my research from living with animals (specifically cats and dogs), I have noticed the following: Bunting or head-butting is when a cat is purposely rubbing his/her head against you but not in a territorial way. This signals comfort and shows that they trust you and can rely on you.
Another telltale sign is kneading. Many pet owners are confused about this and don't understand it. This is basically your cat getting comfortable, although I might be a little uncomfortable for you, the cat is showing you that he or she is not nervous around you, or else it would choose to be somewhere else. To me it is the equivalent of a dog pawing you.
The next obvious thing in my opinion is a cat wanting to be near you. If your cat or a cat in general wants to be near, presuming that it's fed, then take it that this cat wants your love. It is showing that it feels comfortable, safe, wanted, and most of all loved.