Lexus commissioned a fully functional electric car built from laser cut cardboard. It comprises 1700 individual pieces and took 3 months, I imagine the builders were quite card-bored by the end of assembly.
Instructables user JackCarter made this awesome lasercut tank model from MDF. The functional tracks looks great and the laser is perfect for making a repetitive object like that, although they do also provide the files to make a static track if you don't have enough patience for assembly. There are lots of tank models out there but, because this comes with instructions, it is definitely a challenger for the best.
A lot of wargaming models are cut from 3mm mdf, the folks over at Laser Cut Card have opted to use 1mm card instead. They say it gives them more options to make better details and it receives paint better, it's also lighter for shipping. The results certainly seem to agree that it's a workable material. My painting skills couldn't cope with making a finished item like this, they're pretty tearable.
akselmusic on Thingiverse , just released this industrial terrain complex for wargaming. It 's cut from mdf so it's relatively cheap and it's configurable so you set it up in different ways for different games. They're a little plane and could do with some military detailing detail, but because it's thingiverse you can remix it , just don't forget to say tanks.