You dont do that to songs that didnt suck.
Why would you do it to songs that suck? I don't care how good a person is, remixing 'Friday' is never going to even make it tolerable, much less good.. It is possible to remix, dubstep or chop and screw a good song and preserve the originality and what made the song 'good' while also adding new layers.. The only question is how and can the person trying to do so, actually accomplish it. Less is more.
But as I said, I'm new to it and it's hard for me to find things I actually like.. Those 3 are actually the work of youtubing every single band I know.. That's it, out of all the music I know, those are all I found that I would call 'good'.
Oh and by every band I know.. I'm talking every single thing that I ever liked.. I tried googling "Clay Walker Dubstep".. Although that was more morbid curiosity..