Even though I'm willing to try any brand if my funding allows it, and becuase I'm experimental like that, I would have to narrow down my two favorites brands as:

Drustore: Covergirl (Queen Collection)

High End: M-A-C

CG has a liquid foundation that blends so perfectly into my skin that I don't even see it (good an bad because it doesn't cover much) but I was not complaing because it was $8 which is VERY reasonable. My new favorite from CG is the lip perfection lipstick, I'm crazy about it right now. And let's just say I have never purchased anything from MAC that I hated. Their foundation is just AWESOME, their eyeshadows- also AWESOME. M-A-C is well worth the money in my opinion.

Smashbox is making its way into my favorites category but for now CG and MAC are my top 2.

I have to admit I have a soft spot for Smashbox, it can be pricey but then again, if you find the perfect product it saves you spending even more trailing through the not-so good stuff right? And MAC is amazing too. For more drugstore price stuff over here we have a brand called "GOSH" which I LOVE! it has the most amazing eyeshadow pallettes! Also, Barry M is brilliant for its quirky style!

This is a toughie. I love Smashbox and MAC. But ELF has some pretty good things, I love their brushes, so much cheaper than the high end stuff and just as good and their make-up remover, the best I ever found

The beauty product list is awesome! I've tried many of the products mentioned and they certianly do the trick.

As far as best makeup brand, it's hard to choose just one. I'm a drugstore makeup junkie, with only a few higher end products. So my fav drugstore brand has to be Maybelline because of the selection and quality of products. Rimmel is a close second, being trendier and for having a huge color selection as far as lipstick and eyeshadows. The only downside is some stores don't carry Rimmel.

For a higher end store, MAC nails it. They have a great overall line including a big selection of high quality brushes, great color selection w/good color payoff, and foundations/powder for all skintones.

Other products I can't live without include Urban Decay Primer Potion...the best IMO and MAC blush. 

I think I would have to go with Urban Decay for makeup, but I do love Estee Lauder skin care.  But Lancome makes the best mascara.......

My favorite would be Avon!

tarte and mac. mac because they make my hg foundation, face and body

I'm in my 50's and have been a make up whore/junkie since I was 14.  There isn't much I haven't tried!

Faves:

Mascara:  Bare Escentuals Magic Wand  -- no brush...coats evenly and stays on perfectly.

Foundation:  Lancome Lift Renergie    One of the only brands that doesn't cake, turn orange or yellow.  Contains SPF and is moisturing.      Origins is also another favorite, but thewy seem to discontinue items just when you fall in love with them.

Concealer:  Estee Lauder Stay in Place double Wear          The name says it all.

Eye Shadow:  Nyx, Mac

Eye liner:  Stila, Urban Decay

Powder:  Smashbox   I don't use a lot, as you get older powder likes to flock to lines and wrinkles.  With a good foundation, you don't need powder.

Blush;  Never wore it - never will.  I prefer the pale look.

Make up is fun!  Experiment!  Not all brands are created equal, no matter the price.  Take care of oyur skin when you're young and you won't regret it.  And, whatever you do, stay out of the sun or use sun block!

Too Faced is my go to brand. They have quality products, and just came out with their summer collection, including a beauty balm, bronzer, and a fantastic summer eyeshadow palette with colors you don't usually get from Too Faced. I have never been disappointed with their products. Love their new foundation and eyeshadow primer, Candlelight Glow.