Ellingson, Waker + Armanti Edwards = arguably the best big 3 in the league; the Elks also have a big group of promising Canadian receivers to choose from if they want to start 2 NIs there again.
The Argos with Daniels & Rogers as proven CFL receivers, plus a couple of former big NFL resume guys could prove very dangerous; they also have some very good Canadian talent in Brescacin, Noel, Gittens and draft pick Brissett.
The Riders have Evans, Moore, Williams-L and also a bunch of young Canadian guys with good resumes.
The Ticats have a bunch of proven import receivers.
Lots of talent at the position across the league = not sure I could pick a sure-fire #1 ?