Punisher

If there is one character fans want to see most in the MCU right now, it's Frank Castle, the Punisher. The character hasn't fared well in live-action (with three commercially and critically derided films to prove it), but could find quite the home on Netflix and should probably show up in Daredevil first. Daredevil succeeded in paving the way for a darker, bloodier corner of the MCU, and it's easy to see how Castle could walk right in and fit comfortably within it. He's gone up against Daredevil several times in the comics and could prove to be quite the adversary and eventual ally in the series. Both Charlie Cox and showrunner Steven S. DeKnight have expressed their desire to bring the character to the small screen, so hopefully it's just a matter of time before they (and we!) get their wish.