Daniel Day Lewis would be fantastic in "Doctor Strange" as Stephen Strange. Bradley Cooper has long been rumoured as Barry Allen in "The Flash" film. Kevin Smith wanted Jake Gyllenhall for Britt Reid in his abandoned "Green Hornet" script.
Gylenhall was also supposed to have been lined up to replace Toby Maguire for Spider-man 2, when the latter had back problems/ wanted more money. He was also David Goyer's choice to play Bruce Wayne/Batman for Batman Begins, but Christopher Nolan preferred Bale.
And of course, Gylenhall replaced Vinnie Chase for Aquaman 2.
Speaking of Begins, Day-Lewis was supposed to have been offered the role which his Gangs of New York co-star Liam Neeson played in it, but of course, being DDL he turned it down.