A few suggestions, depending on what you're after:
The ultimate in credible country - Johnny Cash (earlier albums for simple singalong fare; later ones for impressive but depressing songs about death etc and of course the two "prison" albums somewhere in the middle).
Great voice and intelligent songs - Emmylou Harris (her 2003 album Stumble Into Grace is lovely)
"Outlaw" country (created as a reaction against Nashville schmaltz) - Willie Nelson or Waylon Jennings.
The inventors of country rock - The Byrds/Gram Parsons/Flying Burrito Brothers (all linked - with The Byrds, their most 'country' album is Sweethearts of the Rodeo)
Guitar-based rocking country - Steve Earle (Copperhead Road is a good starting point)
Sorry none of these are particularly youthful (or even still alive, in the cases of Cash, Jennings and Parsons) but I find a lot of today's country either very 'corny' or very bland (that means you, Shania)