Sigma 70-200 2.8 or Tamron 70-200 2.8?

I'm having a hard time deciding betweent these two lenses. I have a nikon d5000 and the nikon 70-200 and 80-200 is out of the story because they are to expensive, and i need a good lens now, and the 80-200 won't autofocus with my d5000.so which one is better? Sharper? I don't mind weight or which one is longer, i need help please. I do portraits so this is what it would be mainly used for

Added (1). I heard the autofocus on the Tamron version and its pretty loud, and also the Sigma i heard is faster but its not as sharp. Does anyone have sample shots comparing quality?

The Tamron one is pretty awful. The new Sigma is actually very nice. Just make sure you get the latest model.

The only problem with Sigma is their build quality is spotty. If your lens is not up to specs the first time you buy it, return it and ask for a different one; you may have gotten a lemon.

SIGMA! All the way!

It's an overall better lens. Better made, sharper, more durable.

I'd lean towards the Tamron.

DPReview likes them both:
Tamron: http://www.dpreview.com/.../page6.asp
Sigma (new model): http://www.dpreview.com/.../page6.asp

User comparisons tend to agree that the Sigma focuses faster (better for sports and event photography?) but that the Tamron is a tad sharper (better for anything else, including portraits?).

For $1000 you could also get a used Nikon 80-200mm f/2.8 AF-S. The AF-S version will auto-focus just fine on your D5000.It'll also still be worth $1000 if/ when you decide to upgrade to a 70-200mm f/2.8 in a few years.

Or if you're really after a portrait lens, consider one of Nikon's primes: the 85mm f/1.4 or f/1.8, the 105mm or 135mm DC. (Although anything over 100mm might be a bit long for portraits on a DX sensor.)
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added:
Sorry, forget I even mentioned those prime lenses… The only AF-S version is the new 85mm f/1.4 ($1700) and AF compatibility was the entire point of your question. My bad!
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also added: There are a few test shots in the reviews that I linked to.