I often hear that the phrase “very unique” is not a correct thing to say. The explanation is that the word unique means “there is nothing else like it” and as such is already an absolute. So there’s no grades of unique: something is either unique or it’s not — there is nothing else like it or there is someting like it. This is a good explanation, so I agree we shouldn’t use the phrase “very unique”.
 
But here’s the big problem: what are we supposed to use instead? What if you want to say something is unique, but add some strength to your statement? It’s all well and good to tell me what I can’t say, but perhaps you could also tell me what I can say?
 
And, as always, it makes me think of my own teaching. How often do I tell students not to do something, with all the excellent reasons why it’s a bad idea, only to leave out the important part of telling them what to do instead?
 
As a student, this has been done to me a lot when writing proofs. The lecturer could often tell me that what I have written is not correct or understandable, but usually did not think to (or know how to) tell me how to find a correct or more understandable way to write it. I hope I have the presence of mind not to leave students with this frustration — because it is damned frustrating!
 
PS: I think a good alternative might be “truly unique”.