Cosmetics, nope. I used to use Lancóme and Estee Lauder's
eyeshadows and Christian Dior / Shiseido / Lancóme / YSL lipsticks
but you know what, I feel that they aren't really 'better' than
brands like Maybelline or L'oreal! Now, for lipsticks, I use
Avon and Maybelline. Avon has a range that I absolutely love
and it's so much cheaper too!
This colleague of mine says that she has tried all brands of
eyeliners, from the supermarket brands like Maybelline and Rimmel,
to the high-end ones like Christian Dior, Bobbi Brown, and YSL and
she found to her surprise, that the Avon one works best for her and
I was stumped!
Anyways, for liquid eyeliners, I love L'oreal's - stays on,
doesn't smudge, and easy to apply. It's not expensive
either. What more can a girl ask for? 
Recently, I tried Maybelline's Dream Matte Mousse and I'm now a
fan of it! I've spent quite a fair bit trying out all manner
of foundation but they end up being the wrong shade, the wrong
texture, too greasy, too dry, etc. That Maybelline's Mousse
passed the test! 
How about skin care? Facial cleansers, toners, moisturizers,
masks, creams, etc?