"Most advanced and stable 21" desktop you can buy."4.5 starson by Meni
Pros: Extremely fast. Fusion drive best implementation of a hybrid drive on the market. Rock solid Mac OS X. Jaw dropping looks. Best color reproduction in its class. Runs Windows perfectly under boot camp or virtualization.
Cons: Lack of Retina display obvious to those who already own ultra high resolute devices. Apple still doesn't know how to make an ergonomic mouse.