One of the Optiplex I found in the street.
It was also ugly and filthy dirty. After some extensive cleaning, I did a simple clean paint job with black and my favorite blue paint that I like to call deep and soft.
I selected the components that were working from the lot I found, I only added a spare Wifi USB dongle, a 120GB SSD, and a 500GB HDD for datas.
I kept 6GB of DDR3 form all the optiplex I found: 2x2GB and 2x1GB, the DVD player, and the Core 2 E7500 CPU.
I also added an in expensive GT710: this PC will be used mainly as a media center with a 1080P TV. The little CGU is more than enough to play Netflix and blu rays and movies, with sound going to the TV through HDMI.
I don't plan to put any money in that build, so unless I salvage a better processor, and some ram, there won't be any upgrades here.
It doesn't actually need any upgrade: the windows 10 pro experience is smooth, web browsing is OK, watching netflix in 1080P is not an issue. It's just good enough for simple things.
EDIT: turns out I had more spare DDR3: the one now has 2x4GB and 2x2GB. I also pin modded the E7500, it's running perfectly stable on 333 FSB at 3.65GHz, barely reaching 55°C under load.