I'm a Bills fanatic, and here're my take:
Stevie Johnson is still the #1 target, and will be the slot WR when everyone is healthy. Johnson isn't real fast, but may have the best "moves" of any WR in the NFL, and is not going anywhere soon.
Robert Woods is the top outside WR, and will be taking over the #1 target label from SJ13, probably by end of next year IMO. Woods has Reggie Wayne type WR1 potential. When he comes back healthy after the bye and has Manual back at QB, he'll start to show it again.
TJ Graham is technically a starter opposite Woods on the outside (in 3WR sets), but he has no fantasy value. He has shown almost nothing now in 2 years, and will likely be out of football in a year or 2.
Goodwin is explosive & can catch, but is not a natural WR. I see him being like a Dante Hall or Hester when they played WR, but with a little more upside. He should replace Graham next year or sooner, but I don't think he'll be higher than the 3rd option anytime soon.
In dynasty, Woods is far more valuable than Goodwin.