We do "business casual" at my office, which basically means, no jeans, t-shirts or sneakers.
I almost always wear cords or khakis of varying earth tones, lately by J Crew since thieir cuts fit me the best these days. Always flat front, never boot cut, usually in whatever they are calling the "slim fit" that week.
When jeans are not an option, cords (please not wide wale they make you look like an asshole) are then next best casual pants and will usually fly in most dress code scnearios that draw the line at jeans.