Didn't they buff the crap out of Mal recently?
They made Twitch look more like an AD carry with stealth abilities. I like the current Twitch than the old one because he won't be able to stay out of teamfights as long as he once did. Old Twitch was a janitor, like AP Yi.
Evelynn is much more fun to play right now because of her new passive. It feels way more stealthy than just skulking around waiting for an opportunity to strike. You have to play with the bushes and the fact that minions can't even see through your stealth, making lane ganking much more violent. People don't usually pink ward the two bushes in the lane.
AP Amumu was lethal, it was a deserved nerf. Doesn't make him less fun to play, though.
As for Malphite, the reason why he's still picked is because he counters the current bruiser AD top laner meta on a large scale. Try playing Xin Zhao or Jax against him and they're sure to be demolished because they rely too much on auto attacks.
EDIT#3: Man, these edits are really killing me.