I have a 94 XR650L that I absolutely love. It's a bit much for anything too technical off road, but it's a wonderful bike. I also have a 96 Kawasaki KDX200 that is a blast to ride. It's very forgiving in the lower end of the throttle range, and geared a little higher than a typical two stroke race bike.
If you have your heart set on an XR250, I can say that I have ridden them also, and you will not be disappointed! Bomb-proof bikes for sure!