Best mid lane champs

That's like asking what's the best color in the whole wide world. You make your decision, not take others. Play the champs, and get a feel for them. Do not subject yourself to playing a champion because you've been told or otherwise perceive them as "good". Make a champion you like good.

Blitzcrank.

i mean if you're asking for most fun that's a matter of opinion. best right now, brand, zed, yasuo, etc.

yas with that heal on crit mastery is terrifying

I personally love playing

What is currently strong (IMO):

Holy trinity theory: Long range poke mage > Close range CC/Burst mage Close range CC burst mage > Assassins Assassins > Long range poke mage

In theory, wrecks and wrecks but jumps on Syndra and burst the holy crap out of her. In theory of course.