JK

 

Justicar - Where there are laws, there are those who defy them.  And where there are lawbreakers, there are those who hunt them down.  They don't do it for glory; they don't do it for money...they do it because it needs to be done. These are the Justicars.  (From Dragon #290) Requirements:
Alignment:
lawful
BAB: +6
Feats: Track, Skill Focus (Gather Information)
Wilderness Lore: 5 ranks
Gather Information: 5 ranks
Search: 5 ranks
Kensai (Weapon Master) - For kensai, the perfection of ki is found in the mastery of a single melee weapon.  Their body and their weapon become one.  (from Oriental Adventures) Requirements:
BAB:
+5
Intimidate: 4 ranks
Feats: Dodge, Mobility, Combat Reflexes, Expertise, Weapon Focus (with weapon of choice), Whirlwind Attack
Special:
Must own a masterwork (or better) weapon of choice.
Kishi Charger - Cavalry soldiers trained to make the greatest possible uses of a horse's speed and a rider's agility, kishi chargers share a special bond with their mounts and are capable of truly devastating mounted attacks.  Kishi charges generally come from Baklunish nations as well as the further reaches of the oriental lands.  (from Oriental Adventures) Requirements:
BAB:
+6
Ride:
9 ranks
Feats:
Mounted Combat, Rid-by Attack, Spirited Charge
Weapon Proficiency:
Lance (uma-yari)
Knight Protector of the Great Kingdom  - The Protectors are the last remnant of a formerly great order of knights who had pledged their existence to defending that now-defunct kingdom.  They strive to restore the ideals of chivalry before they fade forever. (from S&F) Requirements:
BAB:
+4
Race:
Human, half-elf, elf, dwarf
Diplomacy:
6 ranks
Knowledge (nobility and royalty):
4 ranks
Ride:
6 ranks
Feats:
Power Attack, Cleave, Mounted Combat, Great Cleave
Proficiency:
Heavy armour
Alignment:
Lawful
Other:
Must earn membership in the prestigious order.
Knight of the Chalice - Members of an elite knightly organization, Knights of the chalice are devoted to fighting demons and learn tactics and gain special abilities to help them in their crusade.  (from Defenders of the Faith) Requirements:
Alignment:
Lawful Good
BAB: +8
Knowledge (religion): 10 ranks
Knowledge (the planes): 5 ranks
Spells: Ability to cast divine spells, including protection from evil. 
Equipment:
Magic full plate armor.
Special: Must have demons as a 'favored enemy' or 'foe' and defeated a demon or driven it back to its home plane.  (This results in this prestige class requiring at least one level in Ranger or the Foe Hunter feat.)
Knight of the Middle Circle - These knights are members of the Stargazers organization, and serve the stargazers and their needs.  (from Defenders of the Faith) Requirements:
Alignment:
Good, non-chaotic
BAB: +6
Handle Animal: 7 ranks
Gather Information: 4 ranks
Innuendo: 4 ranks