Hi im new here. Im interested in this firmware and haven't got myself a canon camera yet. Im wondering which is the best camera which supports it?
That a bit like asking "which is the best automobile to buy".
If you want a really nice camera, both the S100 and G1X have full support.
If you want inexpensive to "just try things out" you can get an A1200 for about $80 online as they have just stopped making them.
It typically takes as much as a year after a new camera comes out for it to be ported. Some never get ported. And not all firmware versions get ported for every camera. Probably best to look for a camera you want to own regardless of CHDK status and then look at the CHDK wiki page for that camera and the porting thread for that camera in this forum.
Sorry I can't be more specific. You might want to take a look at this first though :
link>CHDK FAQ : My camera isn't ported yet