This is from an American Diabetes Association Cookbook, but you can make it with regular gelatin and regular cream cheese. I've taken it to potlucks, and even the lowfat, sugar-free version disappears quickly.
Combine strawberry gelatin and 1c boiling water; stirring 2 minutes or until gelatin dissolves; Stir in strawberries and pour into a 10c mold coated with cooking spray; Cover and chill 1 hour.
Combine lemon gelatin and 1c boiling water; stirring 2 minutes or until gelatin dissolves; set aside.
Beat neufchatel cheese in a medium bowl at medium speed of an electric mixer until smooth; Gradually add milk, beating well; Add lemon gelatin to cheese mixture, beating at low speed until smooth; Gently pour into mold over strawberry layer; Cover and chill 1 hour.
Combine lime gelatin and 1c boiling water, stirring 2 min or until gelatin dissolves, chill until the consistency of unbeaten egg white; Stir in pineapple; pour over lemon layer; cover and chill 1 hour.