MIX graham crumbs, margarine and 1/4 cup sugar; press onto bottom of 13x9-inch pan. Refrigerate while preparing filling.
BEAT Neufchatel and remaining sugar in large bowl with mixer until well blended. Add dry gelatin mix; mix well. Stir in peaches and COOL WHIP; spoon over crust.
REFRIGERATE 4 hours or until firm.