I think it's more fun to do cheesy or drinking songs for karaoke. Go with "Boot Scootin' Boogy" by Brooks & Dunn or anything by Garth Brooks, specifically "Friends in Low Places".
I would say your favorite country song, I have not ideal what you like. I know that the faster the song, the harder to keep up if you don't know it very well.
Or or.. "5 O' Clock Somewhere by Alan Jackson & Jimmy Buffet, or "Tequila Makes Her Clothes Fall Off" by: Joe Nichols
I always loved the duet "its your love". Its at a medium octive most of the way through
Homewrecker by Gretch Wilson :D love that song
before he cheats - carrie underwood
she's country by jason aldean