1、LoveVery personal. Used between lovers, family and close friends.
2、CheersVery casual. Used between friends. Can be used between coworkers if you want to appear very casual, at the risk of sounding unprofessional.
3、Take careCasual and used between friends.
4、ThanksorThank You'Thanks' is very casual and 'Thank You' is formal. Usually used in a business setting. 'Thank You' is a great way to end an email to a stranger, especially if you are making a request or asking a question.
5、YoursorYours TrulyorTrulyCasual or Business casual. A more personal, but still polite way to end the letter. You've probably met the recipient in real life.
6、BestorBest WishesCasual or Business casual. A polite way to end the letter. Can be used between friends or strangers.
7、SincerelyorSincerely YoursorYours SincerelyCasual, Business casual or Formal. The standard letter ending. 'Sincerely' is the most versatile ending because it can be used to end either casual or formal correspondence. If you're unsure about how to sign your letter, use 'Sincerely'.
8、RegardsorBest RegardsBusiness casual or formal. You would use this if the recipient is someone you haven't met in real life.
9、CordiallyFormal. Used in business correspondence when the topic of the letter is serious. Sometimes used if there is a conflict between the sender and the recipient.