These are what I used to get to 1000 amity with each of these NPCs. Not saying it's the best, just what I used. ;)
Best used in conjunction with this list of amity knowledge NPCs. Note that some of the ones I list are traders, and not amity knowledge NPCs.
Also related - knowledge locator.
Altinova
Deve
Just wave
Ganin Arth
Aseh> Tantu > Ein Greid > Joaqin Mars > Herawen
Haley
Mediah merchant's union > Leader of altinova > Shen merchant guild > Exile of Bareeds III
Lashir
Practice partner of an apprentice sorceress > Ancient character decoration > Weikid Taha's speciality > Wrapping up the day > Tarif decoration > Ball of cobweb > Ignar's snack > A real blacksmith
Lucy Benkum
Extremely variable, don't go above 2 rounds unless you feel like gambling even more. :P
Maudi Budar's insight > The missing upper class > A marvelous discovery, rare chest > Strategy is simple > Threat of savages
After you get her first knowledge (logical messenger)...
Maudi Budar's insight > The missing upper class > Logical messenger > Strategy is simple > Threat of savages
Verosi
Just wave
Woodrey
Just wave
Zigmund
Helm hunter > Helm crusher > Helm tribe forge > Helm iron shield
Calpheon
Alchem
Troll Hut > Troll Cow > Troll Barricade > Young troll ox
Harden
Gabril > Lilvayne > Philliberto > Basillan
Lamiro Ladans
Giovanni > Philliberto > Basillan > Bianstimi > Gabril > Lilvayne
Glish
Bach
Coco Elda > Fatoos > Amadeo Alejandro > Hunt
Larc
Xian alliance > Outlaws of the Slum > Crisis in Kalis > Hope of peasants > Honor, the final decision
Heidel
Joel
Puia > Caresto > Siuta > Joel > Melissa Brady > Olivia
Radolf
Caresto > Puia > Joel > Melissa Brady > Siuta > Lara > Dora
Siuta
Puia > Joel > Melissa Brady > Siuta > Dora
Keplan
Hamir
Rhuthum wizard > Rhutum elite warrior > Rhutum tower > rhutum elite archer > Rhutum hut
Old wisdom tree
Lumen - she is insanely easy to get amity with using this knowledge set... 400+500 per round.
Stone crab > Stonescale devourer > Stone rat > Red boar
Olvia
Nadia Rowen
Sterie > Vongole > Daphne DelLucci > Martina Finto > Adrian Loggia
Eren Ross
Valencia
Awana Dilla
Witches & alchemists > Forbidden land > Frenzy of the skeleton king > 125 witches > Monastery on the cliff
Burita Allon
Burita Allon > Arenda > Zahad > Wacky Toshi
Rabam
Secret Guards I > Secret Guards II > Resurrection of Belmorn > Origin of Earth > Caphras secret lab > Origin of ancient light
Tasaila Hilla
Just wave
Yis Kunjamin
Vatputa > Ossa Dilla > Tanzine > Kiyak > Salebin
Velia
Mathias
Sterie > Emma > Martina > Daphne > Vongole > Darifu
Santo Manzi
Hans > Igor Bartali > David Finto > Islin Bartali > Egrin > Abelin
Western guard camp
Luke
Clorince > Shiel > Santo > Bahar > Tranan > Pulvio > Eileen