Here are my favorites for you to add to your bookmarks:
Chanel - Chanel Makeup - Chanel YouTube
Chanel's YouTube chanel is adictive viewing indeed with tutorials from the phenomenal Lisa Eldridge who makes applying a Chanel eye shadow quad look as easy as pie, the cutest animations using products and heaps of interviews with Karl's IT girls. This will only make you lust longingly after the luxury houses beauiful products even more.
OPI - OPI Site - OPI App
The OPI site has a bounty of information about the brand - anything you could ever want to know about nails or OPI is on here. There is also a blog by Suzi who is a real nail nut - she should really come to Nail Polish Addicts Anonymous. Then there is the OPI App which is really the best time waster ever, it allows you to pick your skintone and then apply a colour! Procrastinate on this when you are on your way to the salon next to get your nails done.
Yves Saint Laurent - Yves Saint Laurent Site - Yves Saint Laurent App
Yves Saint Laurent or is it now Saint Laurent? Are killing it on the app front for reals, they have made makeup so much fun on your iphone. Look here I am using the ColorMirror app, which lets you apply YSL products to a models face and upload a photo to test products on yourself - warning this comparison makes you want to buy more makeup and is a total self esteem buster.
Lancome - Lancome Site - Lancome YouTube
Lancome was the first brand to recognise the online YouTube beauty community by naming Michelle Pham an ambassador for the brand. How cool is that! They upload very regular tutorials for new products which is a great way to translate products which at first may seem quite intimidating to use.