Annie, league of legends. What do you think? Pros and Cons?

Annie is often overshadowed by other AP carries, however, she really excels in crowd control (CC). When she mids, she's usually much weaker than the enemy AP carry, but once someone ganks mid, Annie's combos really end fights quickly:

W -> Q -> auto -> E -> auto -> R is usually one of her higher damaging combos.

However, Annie really shows her weakness against an enemy such as Lux. Since Annie is neither long range nor huge damage close range, she's very easy to be pushed back and if she's caught in a bad position, she can be killed quicker than most AP champs.

There's a reason why she's cheap, but, she's a great champ to learn with. Once you get good with Annie, investing in a character like Twisted Fate or Veigar is recommended.