The Express pants don't work for me either.
I think everyone's already made most of the suggestions I would make. Talbots, Ann Taylor (maybe online because they have a greater variety of fits), Target's Merona line, and new to me recently, the Worthington brand at Penneys. All of these have curvy cuts, and I have found that if I want a fitted look I go curvy cut in my regular size, and if I want more of a slouchy trouser look I go a size up in the more rectangular cut and wear a belt.
Also, I am a big fan of the work trousers from Eddie Bauer. I don't know if they carry them in store so you may have to order from catalog/online, but they are returnable in store if something doesn't work out. The curvy cut is called Blakely and they have them in several different fabrications.
If budget is a concern Old Navy has some decent work trousers and they're always having sales and free shipping deals. The fabric isn't as swank as pricier brands but they can be real workhorses for the cost.