I personally have an Acer 3820tg that I've had for about a year now. i5-430, 4gigs of ram, 500gb drive. I upgraded the memory to 6gb (had some lying around) and switched the 5400rpm drive for a 7200rpm. When I have the cash to spare, I'll put in 8gb and a SSD which should speed it up more. I run CrunchbangLinux (debian + xfce) upgraded to Sid repos instead of Squeeze. The only problems I have with it are the video switching can be a pain (solved with a bios mod that lets you disable the ati card, which I don't really use much at all) & the usual annoying broadcom wireless that means you need to connect wired to get the driver the first time or have the .debs downloaded first.
The model is a bit older now but the specs are good and you can probably find them quite cheap now. There is also a second gen version (3830 i think is model?) that has most of the same specs except second gen i5, usb 3 & i think nvidia instead of ati video.
The model is a bit older now but the specs are good and you can probably find them quite cheap now. There is also a second gen version (3830 i think is model?) that has most of the same specs except second gen i5, usb 3 & i think nvidia instead of ati video.