Here are some of my favorite sites that have coupons that you can print out.
These sites have printable coupons, and YES sometimes there are ones that will triple. Not all of them will, some are marked with "Do Not Double/Triple" but some are not.
Here is a list that I have found so far that do not say Do Not Double/Triple
these come from couponmom.com
Wacky Mac Pasta (and this stuff is good)
Land O Lakes Butter
No Yolks Noodles
Dominos Sugar Products