Blue Castle original combat / work trousers for me. Available in olive, black, green and khaki. They are tough but fairly lightweight and they have a draw cord closure on the bottom of each leg so handy for keeping out the creepy crawlies. They have got buttons on the inside for using with braces and metal buckles on the outside to adjust the waist size by an inch or two. I buy mine for less than £15 a pair and they last a fair while. I've had loads of work and bushcrafting trousers from £10 a pair to £110 a pair and I can honestly say these are the ones I prefer.