The most triple's I've ever taken was 14, and I've taken them around 7 times.
It had to have been the stupidest thing i have ever done. Sure, it was fun as fuck, but not worth taking the chance of dying.
My best friend took 16 this year on 420, it had been her second time taking that many, and her third ever doing it. Because of the fact that she had to act sober, she got really stressed. Her heart rate sped up too much and this next thing i know i get called out of class and got told she was in the hospital and that she was alright, but had a heart attack. I now vow to ever take them again. I still do other things, but not them.
I know i probably sound really stupid, but it really is not worth it. If you want to have the same high, with less risk, Robitussin makes a formula called "Maximum Strength Cough" which the only active ingredient is DXM. Unilke Coricidin Cold and Cough, it doesn't have Chlorpheniramine Maleate in it, and that is what causes the heart problems.