Marvel: Ultimate Alliance
Marvel: Ultimate Alliance lets players create their ultimate team from the largest superhero alliance ever as they engage in an epic quest to determine the fate of the Marvel universe. Players can control their own completely unique team by selecting from the largest roster of legendary superheroes ever assembled in one game. Through the epic campaign, the heroes will battle, team-up, and interact with over 140 characters from the Marvel universe and ultimately confront notorious villains. Use a universal team upgrade system to balance your heroes' powers, or customize each member to maximize their effectiveness. In addition to engaging in the epic single-player storyline, you can converge in battle, online or offline, against the world's most evil Super Villains. Switch between cooperative and competitive mode to partner or challenge up to three other players.
Steam User 6
One of the best Marvel games of all time. More of a blast with friends in local co-op than solo though. Packed with missions, enemies, plenty of different heroes to use which all have unique moves & specials. One of its tragedies is the fact that it's completely gone from digital existence. The Steam key for both games is around $1,500 which you can buy an entire PC with. Hopefully one day it will be back.
Steam User 1
It's a shame this game is off the market, it is nostalgia incarnate. Loved this game growing up, doesn't hit as hard now but it was definitely worth buying before they took it off the market.