All depends on how much stuff you want to fit in there, if you want a small form factor mobo or
a full size atx style. Also, if you like to game or overclock, then you want a case with excellent air flow.
Usually a full size case, will flow air and cool the components better than one that is jam packed of parts.
And of course, space where want to put it is an issue. A large case is also easier to work inside as regards
to running cables, adding or removing parts, etc.
I would get the large full size one myself.