Where can I get a PCB gerber file to test the ability of a PCB manufacturer

I find a new PCB manufacturer, they provide very great price service.and I want to test their ability to manufacture. so I want to know where can I find all-sided test gerber files. thanks!

if you have a favourite (smallish) board and EAGLE - make the gerbers yourself!
or share the company here - someone may have experience already
cheers
Mike