"Everything and a bucket of paint."
The West Madison Home Depot (this one) is the nicer of the two Madison Home Depots. Home Depots are a massive cookie-cutter franchise; appearances, inventory and service are consistent between the stores.
Home Depots is heaven for gardeners and a heaven/hell for builders. There is a massive learning curve for seeking inventory as a builder; the items are placed in curious locations throughout the store. Some goods you may expect to find next to another may be several aisles away. Also, it is a little overbearing to see items stocked virtually a mile high. Gardeners, fortunately, do not have to worry about these issues.
Most stock peak at several feet high and everything is right where logic would place them; in addition, the quality of the plants and flowers reach surprisingly splendid levels of luster. When I visited Home Depot to pick up potting soil; I was so impressed with their flower / vegetable inventory that I made $60 in unanticipated purchases (which is hard to do with their famously low prices).
The service is usually friendly and helpful throughout the store, but like my experience, seem to be most available when you have the least use for them.
Visit for exceptional value, and a lesson in good/bad inventory practices; it's certainly not you local hardware store / flower shop.