Honestly, it's been largely predictable where it hasn't been frankly outrageous. Six seasons and it has mostly stuck with Random Krypto-Freak of the Week or Who's Gone Evil Now, which they really shouldn't have needed after Season 3.
I don't mind the Clark-Lana romance. It's LEX-Lana that I mind, along with her spider-queen moments of near-Lexlike evil. Total soap opera, especially since they took some pains early on in the series to make sure Lana KNOWS what a bastard manipulator he is. Like, seasons ago. Romance between them? Only in the soaps where everyone must eventually marry everyone else.
I feel they squandered Brainiac, they definitely squandered Zod (those two are the things seasons are made of), Jor-El has been made out to be some kind of near-omniscient sociopath. And say it with me...Martian Manhunter lived on Mars thousands of years ago before he was brought to Earth. He did not in any way, shape, or form, work as Jor-El's lackey. If not for his vulnerability to fire, he would wipe the floor with nearly anything they come up against...he's Superman with telepathy and shape-shifting powers.
And while I love the character (she's probably the best thing to come out of this show), Chloe's power kinda sucks. I'm thinking Lana either stepped onto that van and neatly avoided yet another death or Chloe is gonna cry on a piece of her. And regrow her. Or something equally inane.