My personal preferences:
Pete Ross (and mention that he and Lana Lang are divorced. She's over it, he isn't, really.)
Jose Delgado (as Gangbuster, or maybe he's give up being Gangbuster, but he's a good character regardless)
Jerry White (yes, he's still alive, and no, he's not Luthor's son)
Ron Troupe (he's only been seen in flashback -- establish that he used to be married to Lucy Lane and he got custody of their son, Sam)
Guardian (the Jim Harper clone -- as far as I know, nothing's been done with him since 2010)
Linda Danvers (just once would make me happy -- and yes, she should meet Kara)
Other possibilities?