I have a rather large collection of nail polish and OPI represents a third of my hoard! The great thing about OPIs is their large range of colours and even better are the collections they release throughout the year. Since they have such a large range, you can easily find a work appropriate pink, date night red or sparkly gold for New Years.
They also wear (mostly, some pigments will always chip more than others) like iron on me. I can get over a week's worth of wear - but this is also due to figuring out a base and top coat combo that works. OPI have also started releasing different types of polish, such as OPI GelColor and in the future, OPI Color Paints for blending your own.
I am in love with OPI polishes. To begin with the price put me off a little bit, but then I tried one out and OPI is now one of the only polishes l'll use.
The colour range is extensive, varied and fun and with when applied to clean, buffed nails with a base and top coat it lasts for days longer than most cheaper nail polishes. This is a huge plus for me as I work in early childhood, so I wash my hands about 20 times a day.
Tips: Make sure you prepare your nails by cleaning, buffing, and applying a base coat first. This will make the polish last a lot longer.