What do you think of the mac mini?

i have a keyboard,a mouse,a screen,why not a mac mini to complete the whole damn thing. I want to know what people think and their experiences with it.please let me know the ups and downs,and also does it get wireless or do i have to plug in the USB flash drive that enables or catches more wireless internet in the house. Also is there a way to expad the USB plug in on any computers?like make extra spaces for more USB connections?