What champs should I buy?

So I have approximately 10.5k IP right now, for the past few months I've had no idea who to buy, so I just kept saving up IP. I was at 27k at one point before I asked some random person to give me several champs to buy and so I bought them. But I want your opinion on what champions I should prioritize buying out of the ones remaining for me. Here is what I have left to buy:

Basically, please just help me order these champions into the order of importance or priority that I should buy! Thanks!