Your FINAL BLOG topic is FREE CHOICE! You could blog about whatever it is you want, except what you've already blogged about! You could go on a rant or you could simply blog about something important to you.
Since this is your FINAL BLOG OF this school year do something creative! Write about something you feel important or something you would like to tell your audience for the last time this year. Talk about something that you thoroughly enjoyed or something that bugged you. Do something UNIQUE!
You must remember your audience. It is not simply me (Mr. Katz) reading this blog!
If you will be ranting about a certain individual, you need to leave their name out of this. You could give them a pseudonym or simply leave their name as anonymous.
Make sure your language is appropriate. Do not go on swearing tangents.