I am not familiar with the term "miditower". Does it have something to do with music?
Here are some typical case designations:
atx full tower
atx mid tower
atx mini tower
micro-atx mid tower
micro-atx mini tower
micro-atx slim tower
The most common size is the atx mid tower case. The mid tower cases have a range of sizes. Here is a link to a sample of some mid-tower cases:http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=2010090007%201054808287&bop=And&ActiveSearchResult=True&Order=RATING
The very first case in the list is the Antec Nine Hundred. It is the most popular pc case with game enthusiasts. According to an email I received from newegg.com two days ago, the case is their all time number one best seller.