I don't own a long list of purple nail polishes, but I do have a favourite and it is one of the first OPI's I ever purchased :) Aww.
It is 'Purple with a Purpose'
To me, this is the perfect shade of purple. Not overly dark, not overly bright either - just right and I applied two coats. The formula consists of micro flecks of multi-coloured glitter, impossible to capture with a photo. In fact you cannot really notice it on the nail, but what I feel the glitter provides intensity to the colour. It isn't a boring purple which you just keep on for a day because it matches your outfit, it is a beautiful deep grape colour which applies like a creme but shines like glass!
This polish though, the brush in my bottle is extremely wide. And I'm talking almost as wide as my nails wide. Has anyone else noticed theirs to be the same?! I ACTUALLY don't mind the wide brush, however it is tricky and can make coats a little thick. But I mostly apply thick(ish) coats anyway, so that doesn't matter me. I just wanted to point this out, because I have yet to come across another OPI with the same type of brush....
Hope you like! :)