Worst thing you've ever read

[Lord Seth]

Any book based on a computer game (especially Planescape: Troment and Baldur's gate came to my mind)

Are we talking just computer games, or also video games? Because I remember those Nintendo Adventure Books (based on Super Mario and The Legend of Zelda) were pretty fun.

Also The Black Magician trilogy by Trudi Canavan - I can't realise why many people hate twilight but have no fealings for that one.

Easy one. People have heard of Twilight.