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
Although I will occasionally pick up a bottle of Revlon or L’Oreal polish at the drugstore, I think OPI is the best polish out there. They have great, bright colors with a lot of pop, which is what I like, as I use them on my toes, and that splash of bright color always cheers me up, even on the gloomiest winter day.