It's a great resource with dedicated threads to just about any dual sport or adv type bike you can think of.

You might also consider the WR250R. It seems to be fairly popular choice these days.

I have a 2001 DRZ400S and it's a great all-around bike. It's a popular dual sport that basically hasn't changed in 19 years of production - aftermarket parts and accessories are plentiful. It was my main mode of transportation for many years and never let me down. These days, I mostly use it for trail riding and fire service roads.

I also just plated my son's 2015 WR250F. It's a great bike and a lot better on the road than I expected. It's fuel injected and gets great gas mileage. Even so, the fuel tank capacity is a bit too small, but there are aftermarket options that will increase capacity by a gallon or two.