I think Monster Hunter and Pokemon need to be in their own teir above Animal Crossing and Dragon Quest for biggest current franchises.
As a franchise they are currently significantly bigger in Japan even if individual game sales are similar.
Animal crossing has thus far only been able to prove that it can sell one big game a generation, while Pokemon and Monster Hunter have proven over the past few generations that they can sell many big games every generation. If the new Animal Crossing game on the 3ds ends up selling really well then I would say Animal Crossing is of similar popularity to Pokemon and Monster Hunter.
Franchise 3ds sales
Pokemon - 8.06mil
Dragon Quest - 3.41mil
Animal Crossing - 4.1mil
Monster Hunter - 7.94mil