I'd have to agree with the others and say OPI although I really love Essie too.

They're both somewhat expensive here in Australia but I order both of them from a website back home and it works out to about $3USD per bottle including shipping (depending on the exchange rate of course) which is WAY cheaper than here.

I also buy an OPI quick dry product which may be what the others are talking about: it comes with a dropper and you just drop one little blob of product onto each nail. Not sure how they do it but your nails are completely dry in record time. Love it.