Best: Warcraft 3. Turning a strategy series into a strategy RPG was so great, it spawned a new game genre with dota-like mobas. And the game was near-perfect.
Worst: FFXI, the moment I stopped playing my favorite video game series. I know it was huge and people were addicted, but turning FF into a MMORPG started the downward spiral of the series for me. I only played 12 after FFX for 5 minutes, that's as far as I got in FF after X.
Honorable mention: Wind Waker, the moment a part of my inner zelda fan died. Zelda was not a series for kids, it was for everyone and a cool series that has a great aesthetic. WW ruined that during an era when Nintendo was competing with huge PS productions like FFX, which looked incredible.







