I had the chance to drive on the circuit Carole (france), in the 90s, this crazy machine :D ( image just to illustrate this)
(http://www.france-troc.com/ImgUsers/annonces/2014/10/758335/3a287j77hk.jpg)
My "dream" machine is a mix between an old school supermotard and a dirt tracker :
(http://i42.photobucket.com/albums/e311/mgrau/bsm2.jpg)
The day I'll have my place to modify bikes, I'll probably try to make this one first ;D