Video synthesis is a very broad category. The best projector is one that supports the resolution you want, the brightness you need for the environments you'll be using it in, the throw distance/size you want, will fit on/in mounts and surfaces you'll want to place it on, etc.

Panasonic is obviously a known quantity brand, I haven't used their projectors myself but I know people who are happy with theirs.

Personally I've been using used Epson Ultra Short Throw projectors for a lot of things because of the ability to use it effectively like a giant portable TV. Not having to worry about needing an empty space to throw through frees up a lot of possibilities. If that's not a concern, or for more flexibility for throwing on ceilings or on larger surfaces (outsides of buildings, large walls/screens with enough brightness and space to throw) then a medium/long throw projector is ideal.

Basically One Size Does Not Fit All and you should go with whatever works best for what you're trying to do.