Dragon's Demand (paizo) Run and Play
We Be Goblins (paizo) Run and Play
We Be Goblins, Too! (paizo) Run and Play
Rise of the Runelords AP (paizo) Run and Play
The Harrowing (paizo) Run and Play
:) at least those are my top 5.
Kingmaker for sure. Play it if you are confident your GM can run a sandbox well. Run it if you are very creative.
Iron Gods.
Resistance is futile.
Rise of Runelords, Way of the wicked (3pp), kingmaker, Curse of crimson throne, carrion crown.
All of them as player or GM. I think Way of the Wicked books 1 and 2 are just plain awesome, best 2 books imho.
Most of the content is available for free on various websites (D20pfsrd.com , Archive of Nethys, etc). For specific books, the "Ultimate" line usually has a lot of useful content, as can the "Toolbox" soft covers. Unchained has some useful optional rulesets, as does Ultimate Campaign.
Slumbering Tsar if you have ambition.
1. Way of the Wicked is excellent my favourite campaign so far and the highest level our group has reached in many years. Run or play.
2. Skull and shackles is great if you are willing to put the work in. Run.
3. The Enemy Within Campaign by Hogshead Publishing (Shadows over Bogenhafen, Death on the Reik, Power Behind the Throne) as such good stories. Run.
4. The Night Below (AD&D Underdark campaign) Run or Play
5. Kingmaker (Though my advice is to keep the campaign rules behind the scenes and never explain the mechanics of what they do, just get them to tell you and work out the result for them. The campaign system is too easy to break by players that study it).
So many good ones to chose from but these are my favourite campaigns in the last 20 years.
For Way of the Wicked I don't think anything beyond core is necessary. Advanced players guide would be very useful there are several npc's who use classes from it, also it introduces traits which are used in the campaign.
My players have found bits from all over the place useful.
For Bestiaries Bestiary 1 and 2 are useful particularly some devils from 2 turn up as do some good celestials.
I have used some bits from the Book of Vile darkness but not much and that is a very old book. There is some good advice and discussion in the product threads for the way of the wicked books on these forums
WotW has the stat blocks of most things printed, I don't think you need a lot of things to run the NPCs. It comes with an antipaladin archetype which is LE, and works better for the campaign. Other than that, you'll need the books that your player are going to use. Do if a player wants to be an occultust you'll need "occult adventures" and so on.
Haunting of Harrowstone
Curse of the Crimson Throne
Rise of the Runelords
Death in Freeport
Against the Cult of the Reptile God (Pretty sure it doesn't count, but, I luff, luff, luff it.)
As far as modules go, Way of the Wicked is a great evil AP so far!).
No response from Deepmar is also pretty good.