First off, I want to say this idea came from fellow creator, Jacob Craig. He did a top ten list for possible Iron Man replacements. It's a great article to check out, click here to read!
Also this list isn't in any kind of order. I just enjoy numbering it to help keep it flow.
1. Eric Dane-
Reasoning: He just looks tough and gritty, plus he has the acting credentials to back it up, he's been in things like X-Men: The Last Stand to Grey's Anatomy. He's impressive and he has the Frank Castle looks to back it up.
2. Jon Hamm-
Reasoning: He is great in nearly everything he's been in so far. He looks very similar to Frank Castle from the comics, but he has this weirdly dark side to him that makes he a great pick for The Punisher.
3. Gerard Butler-
Reasoning: He has proved time and time again that he can pull off the tough guy with a very dark past if he was casted as The Punisher I would be ecstatic.
4. Nick Apostolides-
Reasoning: I believe if you watch the film, The End of December, it says it all. He's such an excellent actor! He would be great as The Punisher.
5. Jeffrey Dean Morgan-
Reasoning: He was amazing as John Winchester in Supernatural, his performance blew my mind. He would have no problem playing a late-in-his-life Punisher.
6. Joe Manganiello-
Reasoning: He is absolutely ripped, plus there are a ton of dark elements he could bring to the table along with his fantastic acting.
7. Christian Bale-
Reasoning: Bale proved how intense of an actor he was between films like Batman Begins and Public Enemies. He's a wonderful actor, I wouldn't be mad at all if he became Frank Castle.
8. Michael C. Hall-
Reasoning: WATCH DEXTER. I can't stress that enough. It is one of the best series of all time until the last season. But, Michael C. Hall is fantastic as a serial killer pretending to be normal, it's wonderfully creepy. He would be an amazing Punisher.
9. Keanu Reeves-
Reasoning: I heavily rely upon his performance in John Wick as inspiration for his casting. He is one badass action star and could portray The Punisher well.
10. Henry Cavill-
Reasoning: He is no stranger to comic book roles, obviously being Superman. Of course he can't because once again, he's Superman. But, in Immortals he showed off just how intense he can be, and he's a big dude so he can play Frank Castle very well.