One of the first brands of nail polish I ever purchased for myself was Sally Hansen. At the time, I bought it because of the price. I continue to buy and wear it because of the quality.
Even at half the price of some of its competitors, Sally Hansen puts out a quality product. The Hard as Nails Xtreme Wear line of nail colours is particularily good. It lasts long and is resistant to chipping. It also seems to protect my nails. I have very thin nails that easily chip and tear. As odd as it may sound, my nails seem stronger and protected when I am wearing Hard as Nails nail polish.
Out of every colour and shade I have tried, there is one that I would never be without, and that's the basic clear coat. It goes great on top of other colours to protect and add shine. It's good for freshing up a professional manicure. But most often I simply wear it by itself to to add a little shimmer to my otherwise plain nails.
I also use the Xtreme Wear clear coat for an out-of-the-box purpose: Jewelry Making. It does an excellent job reinforcing the knots I make in the twine to secure beads or attatch clasps. It hardens the knots into place and helps water-proof any exposed twine.
Whatever the purpose, I think the basic clear coat makes a great addition to anyone's collection. And whatever the colour, Sally Hansen Hard as Nails Xtreme Wear is an excellent choice when it comes to nail polish.