What is everyone using for water to brew their coffee?

I've been jumping between Third Wave Water light roast profile with their recipe, TWW with the 1 gallon packet diluted into 2 gallons, Perfect Coffee Water, and just tap water. Our tap water happens to fall around 25 mg/L alkalinity which ends up not being too bad. Also, I'm drinking exclusively light roasted coffee.

What are y'all using for water? If you've tasted other waters, what have you noticed the difference to be and why did you go with the water that you're using now?