Carhartt or Dickies for me, but really thinking about a pair of jeans from Men's Workwear, Women's Work Wear, Work Clothing
My wife bought me several pairs of Carhartt's 3-4 years ago at a Christmas sale and they are still going strong, just faded a bit. The Dickies are the cheapest heavier denim I can find for work at $20. The denim on my "nice" Cinch jeans is literally thinner than some Docker khaki's...
Good quality jeans at a fair price is tough now days...