I found a great deal on a W500 for $75, with a t9600, fire gl V5700 512mb, and 4 gb of ram. I plan on putting arch linux on it like I have on my other computers. can anyone who has this computer attest to it's build quality and performance. and how does it do with light gaming hl2 portal 2 minecraft etc.
Did you read the notebookcheck review?
I did but that review was written in 2008 when it came out.
The laptop hasn't changed any in that time period so that review isn't any less relevant today then it was in '08.
As far as games go if the laptop meets the requirements for them and doesn't run hot it should be fine.
For build quality Thinkpads tend to be built like tanks. I haven't dealt with any w500's at work but I've worked on (and in) hundreds of R400's, T400's, T410's and the occasional T5xx's. It takes a fair amount of effort to break one in more than just a cosmetic way. A nice perk of Thinkpads is Lenovo has service manuals available for download and they are really easy to open up and work on as far as laptops go.
I would recommend stressing it (Stresslinux, etc..) to see how hot it gets after popping the keyboard and blowing out the fan/heatsink (just keep the fan from spinning, I block the blades with a pencil at work). If it hits the thermal ceiling under load redoing the thermal paste and pad takes care of the issue the majority of the time.