I could've started this thread myself 3 weeks ago.
Over the course of 2 days I had tried on literally 40 pair of jeans in 3 different stores, not counting the two Goodwills I had visited.
What worked for me are men's Wranglers, I think they call them traditional work style, and men's Levi's 517s. A little high waisted, yes. But these suckers won't wear out at the inseam like those fru - fru Old Navy "Goddess" style lycra laced things I've been using to cover my butt the last six months.
Having said that: It's criminal to me to have to fork over upwards of $50 for a good pair of work jeans. I mean, they're going to get covered in poop, pee, hoof oil, saddle oil, paint.. blah blah blah. Apparently I'm not the only one. I guess the fact that Goodwill is sold out of good work jeans is a testament to how poorly the economy is going, too.