I have ridden all of these. KTM 200, very light, very fiery, tall, maintenance intensive. Is also very fast, superb suspension/brakes. Great enduro bike.
CRM dependable if well maintained, lower than the KTM but a touch heavy. With the right gearing it will tractor up anything but is not as robust as a true enduro but is far better on the road. Can go wrong and spares can be difficult.
Gas Gas, a bit agricultural, v low, v good in tight technical going like narrow wood trails with difficult climbs. Is the most "climb anything" bike i have ever ridden. Also good value for money but is not as well made as the above is a little cheap and chearful. Also not exactly fast it is more trials than enduro.
have you considered a four stroke. Yamaha WR426 very fast , great chassis but tall and hard to start.
XR400 grat all rounder and simple and well made but a little soft in the engine/chassis.
DRZ400 reliable easy going, starts well, strong engiine but a little heavy.