Probably way too much... 4 - 5 cups a day or so. Working graveyard shift doesn't help either. I try to mix it up and drink some quality decaf in between regular cups, or pour 50/50 when getting it from a shop.
A couple years ago, I just decided one day to buy a decent grinder, having always drank Taster's Choice before then. Was never too much into coffee until I picked up a Capresso Infinity and a french press (these days I mostly use the aeropress). After a while I found the good beans (Porto Rico Importing in NYC) and pretty much fell in love with it. Over time I went from sugaring and milking it up to just a splash of milk. There's nothing quite a like a good cup of coffee or 3, especially brewed from recently roasted, just-ground beans. I like tea as well, but it doesn't even come close to the level of satisfaction that I get from a cup of coffee.
I few weeks ago I stepped into the relatively new Stumptown shop here and bought a bag of beans. It makes the Porto Rico stuff look like Taster's Choice in comparison. Not a cheap hobby, I tell ya.