GHS GBZW LO Zakk Wylde

I've been trying hundreds of string brands and models and nothing comes close to the sound of these. The only problem is that you need a compatible guitar with these; the low E is insanely thick and won't fit in the nut slot of any guitar.
You need to file it down, BUT REMEMBER THAT YOU WILL NEED TO CONTINUE USING THESE STRINGS AND ONLY ON THE FILED DOWN GUITAR. If you have multiple guitars and want a really heavy one to play in drop C, just get these and keep it that way. Get a cheap Harley Benton, file the nut for these strings and have fun.
Good luck getting these strings out of tune. You need strong hands even for low tunings. Also, you will need something extremely strong to cut the strings : axe, pincers etc.
If what I said sounds good to you, just get multiple pairs of these. I love them.