Hey, everyone
I'm setting up a new PC myself, and I've found out that ATI cards are pretty cheap/performant these days...
Problem is, I will most likely have a dual boot system as Win 7/Chakra Linux.
I've never used ATI before, and I heard HORRIBLE things about their drivers for Linux.
I mean, won't I even be able to activate 3D effects/ play WoW without rebooting?

Oh, and you've some suggestion for a card (nVidia or Ati) in the 150-200E range that can give some decent performance (I'm thinking about Skyrim/Witcher 2)?
A friend of mine told me the 5xxx series is great, watchya think?
Thanks!

ATI's driver management is certainly not as smooth as NVIDIA's, but it certainly works OK. I run my HD4890 under Ubuntu 11.10 and I've not had many problems.

One area where I have had problems in the past is linking a Linux box up to a TV with an ATI card. ATI's Linux drivers don't deal with HDMI overscan very well. Other than that - no issues.

I'd personally go for a HD 6870. They're really good and go for around €150 these days I think.

I know that the ATI drivers have some problems with Gnome Shell but I don't use it so it doesn't matter to me. They've been getting better so maybe this won't be an issue in a couple of months.
I don't play WoW so I don't know how it plays with the ATI drivers but no game I have on Linux has given me problems. I have tested Prey, UT2004, Doom 3, Penumbra, Amnesia, and most of the games from the HIBs.
My card is an Radeon HD 5770 by the way.

I run arch linux with only ATI cards. On my desktop I run Catalyst and have no problem at all ( ATI 4850 ) and on my laptop I have dual ATI 4200/5400 which I run with the RadeonHD drivers, however the catalysts run fine it as well.

I've had no problem at all, I only regret that theres no *bsd drivers sadly.

I'll chime in as another satisfied ATI/Linux customer. My card is older, an x1400, but it's well supported by the open source drivers.

I had very interesting problems with the Ubuntu/Mint-supplied closed-source ATI drivers (shown in this screenshot, it isn't mine though), they don't like horizontal resolutions that aren't multiples of 64 (like my screen's 1680 width). The latest drivers from AMD's site works good though, as does the open-source drivers.

One of the Gnome3 shell extensions also makes gnome-shell derp out after a while (it's still responding correctly to input, but displays wrong - which can be seen if you switch back and forth between virtual desktops, it'll show the desktop you just switched from but take input to the current desktop). Disabling that extension makes that problem not appear (I think it's Menu or Alt Tab, but I have a bunch of them disabled and don't remember exactly which one was the problem).
... I don't know if this happens only on ATI drivers, or if it happens on Nvidia, Intel, or anything else as well, but it doesn't make a difference whether I use the open-source drivers, closed-source from "Additional Drivers", or latest version directly from AMD's site, only disabling the extension "fixed" it.

My laptop is outfitted with a Radeon 3400 Mobile.

Thanks, everyone! I've figured this configuration out:
Kingston 8GB DD3 1066MHz = 54,90
Radeon HD 6870 1GB DDR5 = 141,55
Monitor = 149 (20")
Athlon II x3 455 = 75,90 || Athlon II X4 840= 85,90
HD 500 GB Fujitsu = 85
Alimentatore = 20
Case = 30
Totali: 566 (Amazon.com)

The prices are either from amazon or local stores (case, monitor, power).
I'm most likely to receive some discounts if I order this all from a store in wich I worked...

I'm still trying to find a good motherboard that can support the AMD cpu and eventually a double ATI crossfire goodness... the ideal would be 50-80 euros.
Any idea?

In this price range, you're limited to AsRock MBs. be careful to avoid cards with a 16x / 4x config. The 870 Extreme 3 provides two pci-e 16x ( 8x/8x in Crossfire mode ) for about 80 EUR

FYI, the Gigabyte GA-990XA-UD3 would probably be better, but I don't think you will find it below 100 EUR

Looks OK, except for the power supply (alimentatore). There are no power supplies that you can buy for 20 euros that will safely power another 500 euros worth of top-quality components. You will be risking a failure of the power supply itself, damage to costly components, or even a fire.

This is the best power supply that Amazon Italy lists for a setup like that:
http://www.amazon.it/Corsair-CP-9020003-EU-Enthusiast-TX750M/dp/B005DPBAVA/ref=sr_1_55?s=electronics&ie=UTF8&qid=1328902689&sr=1-55

And this is the least I would consider at all for a setup like that:
http://www.amazon.it/OCZ-Alimentazione-PC-550-OCZ-ZS550W-EU/dp/B005DCBQYE/ref=sr_1_117?s=electronics&ie=UTF8&qid=1328902926&sr=1-117

For motherboards, ASRock and MSI are the leaders in low-priced motherboards that will take both current and future AMD processors. Look for models from these manufacturers. (ASUS motherboards in the same class are good too, but more expensive.)

ASRock 970 EXTREME3
MSI 870A-G54 (FX)