They are all important in different ways, would be the best answer. The most valuable patents are probably the SLA patents since it seems like SLA technology will eventually be catching on in consumer oriented 3d printers. In my opinion, SLA jetting technology will replace a lot of the FDM devices in people's garages.
I also feel that there are new technologies which will emerge in the coming years ahead which may in fact make many of the patents that still exist, null and void to some extent. Here is an example of what I mean: http://3dprint.com/2236/entirely-new...ic-deposition/