I actually think you could start anywhere because they are tremendously consistent and have pretty much stayed unchanged in their sound since they started. There are some minor differences between their albums but I would say that if you like one you will like all of them (and vice versa of course).
Strange Geometry is my favourite, for what it’s worth, but all of their records are brilliant. There is also a really good compilation, Alone and Unreal, that gives a good overview