In reply to Darkskys:
I have similar problems buying trousers and usually end up buying "casual" fit jeans - the GAP ones are very good and not too expensive.
Definitely avoid Levis 501s, for a start - 758 are possibly my baggiest jeans, but I don't think you can get them anymore.
Paul Smith ones are borderline - I wouldn't want them any tighter!
I'm currently sat in Armani, though