Here are my faves:
ทุกลมหายใจ - โลโซ
http://www.youtube.com/watch?v=PPx8waQ3cXg
I love this song, so emotional, such a beautiful, heartbreaking singing
Loso: Sexy Kot
http://www.youtube.com/watch?v=dwyp2TsW-zI
Because of the guitar riffs

Sek Loso: เสือร้องไห้
http://www.youtube.com/watch?v=2S25pKfNdi8
And I could basically list the whole Loso discography in here LOL

I'm looking forward to discover other Thai artists (preferably from the same genre but basically I'm an all-eater if the music is good!)