Definitely Target. It's only 2 blocks from my house, so I tend to stop there on my way to/from work to pick up "just one thing" and then end up getting suckered in to buying a whole basketful.

The Walmarts by me are really pretty icky. Always messy, always full of screaming toddlers, and always amazingly busy. Target I can be in and out in 15 minutes, even when I do browse... I can't pick up a toothbrush at Walmart without it taking half an hour.

K-Mart.... well, there used to be a K-Mart about half a mile down from my house. I went in there once and it smelled like urine. I think they closed down all but one of them in the city, and thankfully, the one by us was one of them.

Edit: I miss ShopKo. It was cheaper than Target but about the same level of clean.... not as much cute little house stuff but awesome for getting just basic stuff.