Unfiltered tap, also in Michigan.
When I lived in California, we had a Brita-like filter pitcher that we used part of the year, when our water was primarily well water (instead of reservoir water).
Tap water, filtered through my fridge. At work, I usually take a bottle filled with tap water, though I’ll also use the drinking fountain there–I just prefer to have it at my desk.
We have a well. So we drink well water.
Tap, refrigerated but not in a filter container. I live in Minneapolis and I think the water is just right.
Plain tap, from Lake Erie.
Tap. Always tap, unless I’m somewhere with sulfurous well water or something. I fill a pitcher at home, the chlorine evaporates overnight, no need for a filter. My boss bought her staff stainless water bottles for Valentine’s Day, so now my department is even more obviously clicky than we were before…
Tap water here. Tucson, AZ. I have a couple of empty bottles that I refill from my tap so I always have cold water handy. But most of the time I just drink it straight from the tap. In a glass, all of you smarties!
Tap water mainly but I have a water cooler in the basement for convenience (water must be cold, ice cold if possible) and for that I buy from a delivery company called Cedar Springs.
Tap water, all day long, and quite a bit of it. I have a 750 ml Camelbak that I fill up, oh, at least 4-5 times a day and drink it all.
Memphis has great water, so tap.
Ew, so gross, so gross! How do you do that? The water here is so yucky! I wish I could drink the tap water here- are you hard of tasting, or what? 
Tap.
This is true, Memphis and all of North Mississippi. The tap water where I live now is pretty good, and I drink a lot of it, but one of the first things I do when I go home is go get a big glass of that delicious water out of the tap. 
tap
Plain tap well water. I can’t tell the difference between that and bottled.
50% tap water run through the Pur faucet filter, 50% Kroger sparkling water.
Ozarka brand, mostly. The tap water here is awful; several of my friends have been advised by their doctors to either avoid it or install a serious filter/softener setup because it was contributing to kidney stones. (Quite aside from its rather vile taste.)
When I move into a house (soon, hopefully), I plan to install a filter system so I’ll have drinkable tap water.
We have a water cooler and buy bottles at home depot. The reason is that DC tap is notoriously problematic
Filtered tap water at home and work. I’d buy a bottle of water maybe once a year. Last time was to take a tablet while out shopping.
Depending on where I am in the house, I’ll either fill up from the tap or drink filtered tap from the dispenser on the fridge door. Our tap water tastes great, the only reason why I get it from the fridge is when I want it nice and cold.