Okay, it's finally finished bugging me- so this is just to be used as a reference for you guys.
There are two words, "your" and "you're" that are commonly flipflopped. I'll keep this brief, but I'll help you be able to identify when and where to use which phrase.
"Your" implies ownership of something. For example, "That shirt is yours." The phrase explains what is yours, and that it is yours.
"You're" is the contraction of "you are", meaning that it should only be used in situations that you can use "you are". For example, "you're the best, Tsun." makes sense, because it can be subbed with "you are".
"Your the best" doesn't make sense.
Don't be afraid of your apostrophe.