A Song of Ice and Fire by George R. R. Martin
My reviews of the five published books.
A Games of Thrones (1996)
The magnum opus that started the madness. Slow to start but soon becomes compelling reading.
A Clash of Kings (1998)
Still compelling and interesting
A Storm of Swords (20002)
Now the books are getting longer. This one is split into two volumes. The plot starts to thin, the number of characters increase and the pacing slows.
A Feast for Crows (2005)
While still a good read, occasional plot developments keep the reader interested. By now we have realised that the journey is more important than the destination
A Dance with Dragons (2012)
Long, tedious and dull.