Rusty #1: Anthony Michael Hall
Here's what Rusty would look like, all grown up, if they stuck with the original 'Vacation' actor Anthony Michael Hall
Rusty #2: Jason Lively
This is what adult Rusty would look like, based on Jason Lively-- the guy who played him in European Vacation
Rusty #3: Johnny Galecki
Adult Rusty could have made a 'Big Bang' if he were played by the 'Christmas Vacation' actor
Rusty #4: Ethan Embry
'Vegas Vacation' wasn't on par with the rest of the classics, but Ethan Embry's fourth Rusty would have made an agreeable looking Dad in the new movie!
Rusty #5: Ed Helms
I'm betting Ed Helms' Rusty will take after his on-screen Dad, Clark!