i think mortal coil is the best so far becuase it keeps getting better and better and it is so had to put it down. it is also the best beacuse it is the longest so far so the action keeps on coming but i think the successivo one will be better because it goign to be even longer !
Book 1, its the best because all the charcters and its all setting the amazing series of books. It also set the rush for the Skulduggery series. Coming in on a close secound is Book 5 o 6 because its getting the story alot più interesting, including new characters, più breath-taking problems and most of all power! But saying all this, I Amore 'EM ALL!!!!!