I don't think the Johnny Cash cover of Hurt was better, it was certainly great and the video struck an emotional chord, but both versions had different yet equally powerful significance to them. Trent's is definitely the bleaker version, but the arrangement was masterful and his delivery evoked complete sincerety and pain. I felt both guys on their respective versions, but I think Trent's remains the best.
I'll try to post much more in the coming days, but for now i'll leave you with a few interesting covers I stumbled across recently. I wouldn't say that the Depeche Mode cover is better due to the vocals, but the production is definitely sharper and more intricately layered.