5. Scarecrow (Batman: Arkham Asylum)
Rocksteady StudiosThere's many highlights in Rocksteady's phenomenal Batman: Arkham Asylum but his battles against Scarecrow would probably top most people's lists. Scarecrow loves to drug Batman up with trippy hallucinogens at three different points during the game and every time it's a wonderful exploration of the Dark Knight's inner demons. The first time sees Batman having to deal with Commissioner Gordon's apparent death (he tries contacting Gordon's daughter Barbara, also known as Oracle, and quite hilariously is met with a "this number is not available" message) as well as discovering body bags apparently containing his own parents' remains. The second time has Bruce reliving that night in Crime Alley vividly (he's even returned to a childlike form as Scarecrow's drugs play havoc with his mind) and it's so well done that the player is thrown as soon as they step into the recreation. The third time is probably the best though; Rocksteady's love for breaking the fourth wall messes with the player as it seems like the game has crashed and returned to the opening cutscene of the game. In fact, we're simply seeing a recreation of it with the Joker as the hero and Batman as the inmate. It's during this hallucination that we finally get around to defeating Scarecrow (previously, we simply stunned him with a big light to get rid of him) and while the boss battle is fairly standard fare, Dr. Crane leaves a considerable impact on the game that makes everything else seem tame in comparison.