OPI has been my favorite nail polish since Jessica sold out - but really, as I have said before, you can use just about any nail polish color as long as you use an exceptional base and top coat. This is their Mexico Collection, for Spring and Summer 2006:

You can buy OPI polish and other treatments at drugstore.com
Nail Polish Colors,
Nail Trends
Julyne, the beauty guide at About.com (do you love About like I do??), wrote a little bit about nail polish for the spring. Via Allure magazine, Julyne reports that the hot colors are pastels, with women from different parts of the country having different preferences:
Women in big cities like New York & Las Vegas are buying pink for spring (try Revlon’s ‘Blushed’ or Chanel’s ‘Natural Pink), while girls in the South opt for purple (a light purple — try Wet ‘n’ Wild’s ‘Lilac Champagne’ or Sephora Girl in ‘Blackberry Purple’).
Those of you who have gotten to know me will probably realize that although I am a Southern gal, I do loves my pink - raaaaally I do!
Nail Trends