My top 5;
1) Kawasaki KDX200/220; can be found cheap with many farkles.
2) KTM EXC200; post-05 are great. Little more money, but a lot more oomph.
3) Post 96-Honda XR250 (or, a 400, if it can be found); air cooled, light, tons of aftermarket goodies available, and, when maintained, reliable as the sun rising.
4) Yamaha YZ250; throw a large tank, flywheel weight, and some good bars, and it won't let you down. Was my woods weapon for 2 years before I went back to vintage. Look for the post-05 models; aluminum frame and upgraded plastics make a huge difference.
5) Honda CRF250X; magic button. Nuff' said.
"The bold adventurer succeeds the best.” - Ovid
I drink the koolaid too...just not the orange kind.