What are the best radiant heating pipes for underfloor heating?

I want to buy a radiant heating pipe. I heard of Pex and Alupex and know that copper ones are horrible to use. Do you know many companies names of radiant heating pipes or a webstite that will help my? I want to install them underfloor and need your help to choose the best one. Please help!!!

View this post on my blog: http://madeinhome.info/what-are-the-best-radiant-heating-pipes-for-underfloor-heating