7. The Lich King (World Of Warcraft)
Activision BlizzardIt's not often that you wait over five years for a boss battle but that's exactly what happened with the Lich King. Warcraft III: The Frozen Throne officially crowned Arthas as Azeroth's newest villain but it wasn't until The Wrath Of The Lich King expansion for World Of Warcraft in 2008 (five years after The Frozen Throne's release) that we saw Arthas' story continue. The player will come face to face with Arthas several times while exploring Wrath Of The Lich King but directly fighting him had to wait until his boss fight, right at the end of The Wrath Of The Lich King in the Icecrown Citadel raid. It's a tough fight where the smallest mistake can wipe a raid but it's also filled with great moments, like being sucked into Frostmourne (Arthas' sword) and helping Arthas' father King Terenas defeat an enemy inside (failing to do so will help boost The Lich King's damage; no pressure!). Fighting the Lich King on Heroic difficulty is still considered one of the best boss fights in World Of Warcraft and while he may be trivial in difficulty now (thanks to the ever increasing level cap), defeating Arthas and closing his story for the first time will always be highly memorable.