I'm a fan of decent selvedge denim – the better made, readily available brands IMO include Edwin, Nudie and APC. The Levis vintage stuff is pretty good too.
Or, you could go 'niche' and look at Studio D'Artisan, Flathead, Sugar Cane or Ironheart to name just a few. They're certainly not cheap but they are usually exceptionally well made, quality denim and often reproductions of original 1950's vintage jeans and workwear.
There's a new UK jean maker called Tender Company. Their stuff is properly made but not sure whether they're actually on sale anywhere yet / pricing (likely to be £££)