Tamurkhan. By far.

It is the most enjoyable fluff for me. A Chaos invasion (what we all know) but done with a new twist and a great and fun campaign both for the protagonists and antagonists.

It is the most enjoyable expansion into the WHFB universe for me in terms of new units which build on existing societies and factions and as well as linking in with the GW money-spinner (this time incorporating a real spinner) the storm of magic (tragic).

It is the most enjoyable book I have seen this year in terms of art- not just the newly commissioned art pieces of the heroes and villains that really inspire us, but the maps, the background, the typography, its just simply the highest quailty ina produced book I have seen in terms of sci fi and fantasy artefacts.