In reply to jonnie3430:
Honestly its all about personal preference, whatever it is wont stay standard for long. I ride a Honda CBF500 which isn't the most exciting of bike but its never let me down, handles itself off road far better than it should and its got a lot of non standard stuff on it from panniers to a high level motor cross mud guard.
it also depends on what type of engine you'd like, single, twin, v-twin, inline 4, boxer and then there's shaft drive and make.
Personally i like the yamaha Tenere (XT600z i think) but in to short to ride one.
The bmw Serato is meant to be good but the paint on the engine cases isn't always great.
KLR 650 are meant to be bomb proof but not always easy to find.
The old Honda XRV750, Africa twin, i personally think is gorgeous although heavy and lacking in power.
then there's the naked road bikes like the old Honda CB500 the cbf500/600/1000 the Kawasaki ER6 is a good shout as well and a personal favourite of mine which they've just stopped making is the yamaha MT-03
you'll get more or less anything up a forestry track, my old man does it on a Honda hornet with the bikini fairing but something where your upright and not loading the front wheel will feel a lot safer.