HD5850, GTX 460 or GTX470 ?

I would recommend the GTX470. It out performs the 5850 and obviously the GTX460. Depending on whether you're gaming and the game itself it can even outperform the 5870. From a price standpoint its not bad and with the new beta drivers for it, it runs at very nice temps. Also its known to scale better than the GTX480. I would say the GTX470.

Ok thanx I am thinking also to buy the GTX 470  

No problem.

Get one with good cooling though (MSI TF2, Zotac w/Zalman, etc.) as it may help lower power consumption, increase card life, and of course OC better.

Gigabyte also offers one of the best coolers for the GTX470 and the EVGA cooler also has a great fin design that cools well.
Here is a link to the Gigabyte OC edition with its great cooler - http://www.newegg.com/Product/Product.aspx?Item=N82E168...

The 470 is the fastest of the ones selected. For $10 extra, the factory OC'd model from EVGA is popular.

http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Yup that's the EVGA one I was mentioning.

Yep, the GB SOC is really nice. I've seen in one review that it at 700MHz consumes less power than a stock card at 607MHz possibly due to better cooling, components or chip. Only downside is that it is 11.5 inches long, so it wouldn't fit in my Antec 300 w/o mods. So I got the MSI TF2 instead (much shorter).

Twin Frozr II is a great cooler also though. I had gone with the EVGA mainly because I love their warranty and support. Plus it doesn't look too bad either.

Yep, the long warranty is nice. Is the Superclocked very different than the reference though (besides clocks)? I see this one http://www.newegg.com/Product/Product.aspx?Item=N82E168... has a back plate (out of stock though).

Yes my EVGA 470 SC came with the high airflow back plate shown in that picture. Other than that, the clock speeds and a slightly altered heatsink design, there's not any other difference.

Ah, well if it included the plate + tweaks it is worth the $10-20 more. I did see one reviewer on the SC page who didn't get the high flow plate and he was not happy.

To be honest it may not even make that much of a difference, the bracket. But the fin design has been slightly altered on the heatsink and I heard that makes quite a difference.

That is good. Well, at least the bracket looks nice  

I prefer the reference design of the GTX series.. Even though they run a little hotter than the custom designs, i still rate the reference design as a tried and tested functional way to cool down the chipset.

They are ment to run in the 70-90oc section and people dont always overclock everything. But this is my personal opinion.

The GTX470 is the best bang for buck at the moment as the prices of these seem to have dropped quite alot in recent times..

Yeah, the 480 is still not worth the money in my opinion, plus it doesn't scale as nicely as the 470 from what I've read. 460 is cheap and all but 470 beats it down on performance, far more than the difference between the 470 and 480. GTX 470 FTW!