I have one pair of "Operator" pants from LAPG and hate them. The design is great but the waist size was small compared to similar pants from 4 other vendors. LAPG's customer service is crap and their website doesn't accurately reflect what is in stock until AFTER you pay for the item. The worst thing about the pants though is the fabric, a blend of cotton and nylon ripstop that is not unlike Terri Schiavo: you're uncomfortable touching, it just lays there and does nothing, and it only breaths with outside assistence.
Depending on the features you want, simple cargo pants could work, otherwise...Beyond Tactical, Otte, Woolrich, SordUSA, and a few others I can't think of may have pants with more pockets or whatever. Hell, hit up sites like Grey Group and SKD Tactical to see what they have and if any of the companies they carry make pants (but the stores don't list them on their website). Also, soldiersystems.net has links to a bunch of companies.