One of the key things that gets me inspired about an army is the background, and if it is accompanied by some great skald work (in the form of short stories, novellas, or novels themselves) then all the better.
Unfortunately I don't really think the Space Wolves have had a good run of things in this department.
I've read all the Space Wolf novels by William King up to WolfBlade. Bill writes a great novel...
... if you like Gotrek and Felix...
...but his take on the Sons of Russ for me is underwhelming. The characters themselves felt very one dimensional, and the chapters always ended the same way (i.e. "Ragnar felt confused/angry, whatever would he do next????? Who could he trust????? Dum dum duuuuuuuummmmmm")
I have not read the two remaining novels in the series, both by Lee Lightner, so can't comment on them. I'm worried it's one of Bill's nom de plumes.
As for the novels Blood of Asaheim, Stormcaller, as well as the short story Onyx by Chris Wraight, the only bit that was really any good (in my opinion) was when the original Wolf Guard Hjortjur was getting chased down and murdered by Inquisition agents in the prologue. The worst bit? A heavy bolter in a Grey Hunters squad. WHERE IS THE EDITOR?? Does Chris not use conversations with Games Developers (or maybe not... "Hey man, write about the Space Wolves you want to read about") or even the content of the actual codexes as a bit of a clue?? (as a side note, I have been wanting a heavy bolter in my Grey Hunters packs for ages). But seriously, no. Just no.
I was particularly disappointed about these novels especially after reading Battle for the Fang (which Chris Wraight also wrote), which I thought was pretty damn good at evoking the majesty of the Aett.
*edit* Wolves of Fenris is also pretty good, particularly Kraken but avoid Wulfen...
Deathwolf audio drama was ... ok. Can't say I have really got into the BL audiobooks. The characterisations (across all the books) are a bit repetitive and I'd rather read the words and imagine how they might sound by myself to be honest...
The Lone Wolves graphic novel is worth a read (Dan Abnett, yay!) even just for the artwork. And the whole Vlka Fenryka thing.
Then you have the Horus Heresy novels A Thousand Sons by Graham McNeil and Prospero Burns by Dan Abnett. These really changed the game about how people looked at the Space Wolves I think. They added a much darker, more calculatingly violent, and downright vicious streak that was not there before. And leather. And bones. And repressed violence. And nasti... ok I'll stop.
Keeping with the HH series, the cameo from the Space Wolves pack in The Unremembered Empire (also Dan Abnett) was hilariously good. The interchange between Roboute and the pack, as well as when the Lion arrives, was a bit of novel gold. I may even have LoL'd at the latter bit. And they were not scared about facing off with the Night Haunter either... I particularly enjoyed that scene.
So which Space Wolf novel do I think is the best? It's not even a Space Wolf novel - it would have to be, hands down, Aaron Dembski-Bowden's The Emperor's Gift. Logan Grimnar with his Wolf Guard on the Grey Knight Battle barge... fantastic. The space battle above the Fang? Overwhelmingly good.
If there is one thing I'd want for Christmas is for ADB to give the Space Wolves the same trilogy love he gave the Night Lords. Damn that man can write so evocatively.
And maybe he can do a Prince of Crows treatment to one of the minor Wolf Lords...
I'm all inspired to go read The Emperor's Gift again, for the third time in the last 12 months... and of course I need to build an Inquisitor and retinue based loosely on Annika Jarlsdottyr... this madness never ends.