The .mts files can be burnt with ImgBurn or Nero, just start a project as a data one. (Simply copy them to the new project and burn them directly like you'd write out some files.)
Or you also want to convert the files so they can be played on a DVD player?
If you want to, then here is an app. As well as many others out there. What output format should you choose? I'd simply go with DivX (since its widely supported on DVD players) if the content and quantity matters, not the quality. If you want better quality, convert them to DVD format. You'll still lose plenty of the quality. (The best way is to "own" a HD media player (which comes with a HDD, hardware HD video decoder, etc) and play it back with that. Or use a computer , connect it to the TV and that's it. (Notice: Playing back HD videos got some requirements, make sure the PC supports the playback.)