An order quashing service of summons is an appealable order under CCP 904.1(a)(3).  The statute does not draw any distinction between orders quashing service of summons for lack of personal jurisdiction (which are final orders ending the case) and orders quashing service because it was inadequately performed (which are interlocutory since summons can be served again by proper means).  Hence, the latter type of order is just as appealable as the former.