In order to unlock this achievement you will need to earn at least a bronze on all 34 Comic Missions.
Five are available to you at the start and the rest are collected throughout the game in the form of Simulator Discs. In order to unlock the Daredevil and Black Panther Comic Missions, you’ll need to collect five of their respective action figures found throughout the game.
These missions can be accessed at any of the five headquarters via the Training Simulator. Because you can fast travel to any HQ from a S.H.I.E.L.D. Access Point, I’ll tell you where the one at Stark Tower is located. With your back to Iron Man Lab, go up the stairs to your left to find the Training Simulator.
Important note: due to a glitch in this game, if you want access to Silver Surfer after unlocking this achievement, be sure to save before completing your final Comic Mission. After completing it and unlocking your achievement, reload your save and complete it again. You’ll then be able to play as Silver Surfer.
For a detailed guide on all Sim Disc locations as well as unlocking all outfits, visit my solution here:Solution for Dressed for Success in Marvel: Ultimate Alliance (Xbox 360)