Of course, they're best known for the weird stuff. As a transplant from New York who believes that the regular cheese slice is the highest human creation, I am horrified by the idea of mac 'n cheese or taco pizzas or whatever oddities are available on a given day. But what often gets overlooked about Ian's is that their cheese slices are very good. So many places just pile cheese on bread, neglecting the third of the canonical pizza ingredients, and while cheese is delicious, at Ian's they take the sauce seriously as well. In my view, it's the best New York-style slice in town.
I've had a few of the less adventurous specialty slices, and they're good too. But don't let all the hype about all the strange slices, or the image of the place as the place where drunk college students go at 2am, deceive you; Ian's pizza is really good.