This guide can help you get multiple achievements in one playthrough.
Including:

The Saint achievement in Dead Rising worth 63 pointsGet at least 50 survivors out of the mall. 
The Humanist achievement in Dead Rising worth 37 pointsGet at least 10 survivors out of the mall. Link:
http://www.gamefaqs.com/xbox360/928326-dead-rising/faqs/4925...Credit: CarlottaMonroe
Don't worry too much if you don't keep up with the times in the guide there is plenty of time in certain parts, this guy must have been an absolute beast to do it in these times.