I'm quite loyal to my beauty brands - I have my favourite for each bit of makup I own. Mascara - Maybelline, Foundation - Mac, eye-lift YSL, Bronzer - Bourgois.
I've been introduced to a new site that is really useful for people like me who like to mix and match beauty brands. The company I work for is promoting the site www.Myfaveshop.com; (brainchild of Maurice Saatchi). In it I can put all of my fave items in one shop to go back to time and time again. It’s like a virtual shopping paradise! 
Got some very sweet 3D graphics.
More importantly I can have a chat with other users when I'm in my shop! comment on their brands vs mine etc. I think it's a lovely way to shop online if your a sociable beauty brand fan.