My fav is OPI, with China Glaze coming in 2nd... I know these are a little pricier, but they last so much better than most other brands I feel it is a value.
I go wild on colors, you won't find pale pink in my drawer, LOL!
My best are (in order) "Sonic Bloom" a metallic denim color (brights collection), "Plugged-in-Plum" a bright purple (also brights), "Dress to Empress" a hot coral (color classic), and their Designer Series "Shimmer" which is kind of a silvery rainbow effect - best used over another plain color, it's more of a topcoat, changing with whatever is beneath it. I also love "Lincoln Park After Dark" an almost black/purple (deliciously dark) - but I really only wear it in the winter - it's too dark for spring/summer. Man - I could just keep adding colors, LOL!
My nails and my hair are where I have fun!

just to add... OPI has a "try-it-on" feature on their web-site:
OPI Try It On Sudio