I wouldn't wear the cheap $4 pairs, but I do have a pair of Nike Gel Sole ones that were about $35 and I LOVE them. They really hold up well and have an arch support to them. I also have a pair of Speedo flip flops, not as comfortable, but they have a leather toe thong rather than the horribly painful plastic ones that the cheap ones have.

Now I just read a disgusting article on the cheap flip flops and they are a magnet for germs, 18,000 types of germs found on them after a week in NYC, including feces. And yes, it did make me wonder what's on mine even though I don't live in a dirty city.