Future Press did an amazing job with their Dark Souls strategy guide (even if a lot of the stats were patched out from under them), so I happily picked up the Dark Souls II guide as well. So far I'm mostly using it to check item properties and stat upgrades rather than as a full on walk through, but I'm glad to have it handy when playing. If nothing else, 460 page hardcover strategy guides have a wonderfully solid feel to them which is reassuring when trying to cope with particularly difficult boss fights in DS2.
Before that, some of the only strategy guides I'd purchased had been the Megaten ones from Doublejump Books:
Shin Megami Tensei: Nocturne,
Persona 3, and
Persona 4. Those were top notch guides, digest sized to match the DVD cases and, especially in the case of the Nocturne guide, impressively thick and packed to the brim with stats and so forth. Alas, the company is no longer publishing new guides but they still exist as
Onionbat Books and are keeping their older guides in print in digital formats.
Finally, going back to my squandered youth, I always loved having the original volume of
Shay Addams' Quest for Clues handy, which proved invaluable for getting through more than a few Infocom games where I was completely stuck. Addams had already pioneered the strategy guide with the
QuestBusters newsletter and Quest for Clues compiled the guides for dozens of classic PC games in a single, glorious volume. I had such fond memories of that book that I recently snagged a cheap used copy of
Quest for Clues II and had a grand time flipping through it and basically wallowing in nostalgia.
FnordChan