If you haven't watched Flushed Away (it is now on cable), you should.  It is animated with CGI, funny (!) done very well with lots of little inside jokes and once I began watching it, I just could not tear my eyes away.
I would try to describe it, but anything I say makes it sound like less than it is.  A rat.  A pet rat.  a walking talking pet rat.  All alone at home because his family is gone on vacation.  And circumstances conspire to get him flushed down the toilet into a bizarre world he knew nothing about...