The only Acer that I've had and with didn't get any problem was an Acer with an Intel GPU, because with Nvidia and ATI GPU all of them that I have tried (the Acer Aspire 5xxx series), all had problems with heat :S....
I personally would recommend an AMD Fusion based laptop because it performs really well at least from a laptop point of view. My laptop only has a minor bug with rebooting that causes the bios to screw up, however the laptop still works when everything is finished.
anyways, the latest development with xrandr will improve the drivers on the fusion hybrid laptops.
Anyways, i recommend looking at the following laptop...
lenovo IdeaPad Z575 (12992PU) Notebook
Like most people said, get something with Intel integrated graphics. The drivers are really easy to deal with and won't make you cry like ATI (sorry, but that's my experience with them). Stay away from anything AMD, anything non-standard, any obscure hardware (which will give you headaches) and you shouldn't have any problems running Linux. :cool:
It is indeed a comlpex choice :S
In one side we have the new Intel GPU's from the Ivy Bridge architecture that are better than my current ION 2 (Nvidia GT218) from my Asus 1215N which is pretty awesome (mostly the HD 4000 from the Ivy Bridge), and they've got the best opensource drivers (normal it is Intel we are talking about).
And on the other side, we've got ATI with their powerfull GPU (that can cost less than the Intel parts and be more powerfull), but that we can't use at 100% because of a lack on the OpenSource drivers, but that are been working on, thanks to the new Documentation.
Ati can still be the best solution in terms of price and performance in my Opinion.
If you need the laptop ASAP, go Intel SNB. AMD's good, if you go windoz way. As for Linux, AMD (open source GPU driver) is still not mature, and wont mature ~2year from the date you buy the laptop (unless you use catalyst). Hope we will have broader option, soon!