I actually think he was pretty well depicted during the first few seasons (although I have to say I'm not a native speaker so his slightly switching accent never bothered me as I don't have an ear for that). Similar to how its happening in the books the viewer only slowly realized how he had influenced every major plotline. Him revealing that he was behind Jon Arryns death and then pushing Lysa through the moon door was his peak, it's been downhill since than, I was already annoyed how they handled the Vale situation, the Littlefinger from the books would've never gambled on Sansa vouching for him.
I feel that with Roose, Ramsay and Tywin gone, they're trying to make him the major scheming villain but as
@Cheesy said in such an obvious way that it just feels forced and stupid.