The most common site of fracture neck of the femur that causes avascular necrosis is -
"The more proximal the location of a femoral neck fracture, the more likely there is to be nonunion and/or AVN". — Musculoskeletal trauma

Thus non-union and AVN will be most common in subcapital fracture and least in basicervical fracture.
Sub-capital
Intertrochanteric
Trans-cervical
Basal