Which surgery has the best results with regards to density? FUT OR FUE ?

FUE or FUT is just a harvesting technique.  It has no bearing on "density" or how close your grafts are place.However many doctors would say FUT (strip) grafts will usually give you better growth.  

FUT(strip or linear) and FUE are different methods to accomplish the same thing and that is harvest donor grafts.Density is dependent on the number of grafts that are being transplanted into a given area and their distribution (how close they are to one another).I recommend a consultation with an experienced Hair Restoration surgeon to determine how many grafts you need and which method is best for you.