This build is for a dwarf. 32 point buy, but there is lots of room for variation.
Initial stats: Str 14, Dex 16, Con 10, Int 14, Wis 14, Cha 8
After racial Mods: Str 14, Dex 16, Con 12, Int 14, Wis 14, Cha 6
1. Ranger 1- FE, Track*, Weapon Focus: Light Mace
2. Fighter 1- Combat Reflexes*
3. Ranger 2- TWF*, Lightning Mace (style)
4. Fighter 2- Improved Initiative*
5. Ranger 3- Endurance*, +1 str
(skills: craft trapmaking 5 ranks, knowledge arcana 4 ranks (CC), knowledge dungeoneering 2 ranks, knowledge geography 8 ranks, move silently 2 ranks, spellcraft 3 ranks (CC), survival 2 ranks= 33 skill points out of 40 + 8 x int bonus)
6. Occult Slayer 1- magical defense +1, weapon bond, Blind Fight
7. Occult Slayer 2- vicious strike, mind over magic 1/day
8. Occult Slayer 3- auravision, magical defense +2, +1 Str
9. Occult Slayer 4- mind over magic 2/day, nondetection cloak, Improved Critical: Light Mace
10. Occult Slayer 5- blank thoughts, magical defense +3
11. Fighter 3
12. Fighter 4- Weapon Specialization: Light Mace*, Improved TWF (Dex 17), +1 Dex
13. Barbarian 1- fast movement, rage 1/day
14. Barbarian 2- uncanny dodge
15. Dark Hunter 1- improved stonecunning, Power Critical: Light Mace
16. Horizon Walker 1- underground (120 foot darkvision), +1 Str
17. Dark Hunter 2- enhanced darkvision (+30 feet)
18. Dark Hunter 3- sneak attack +1d6, General Feat
19. Horizon Walker 2- desert (no fatigue)
20. Horizon Walker 3- plains (+4 spot), +1 Str
The Occult Slayer's magical defense bonuses (against spells and spell-like abilities) synergize well with a dwarf's innate bonus. The +1d6 damage from weapon bond against creatures with spells or spell-like abilities helps against anything from dragons to demons.
Auravision is a free action, though only the presence of magical auras can be found, not their type. Vicious strike is useful if you have to guard a wizard- the readied action to attack does double damage if it succeeds. Nondetection cloak is not as powerful as it sounds- a caster who makes a level check DC 20 can overcome it. Blank thoughts, however, gives immunity to mind-affecting abilities, which is worth an incredible amount. It means, though, that the good will saves provided by the class are rendered irrelevant.
Probably the best ability is mind over magic. A spell turning effect that can be activated as a free action. It would be wise to invest heavily in spellcraft so that one uses it on a worthwhile spell. This can turn the tide of a battle in which magic is involved!
Skill choices early on in the build meet the pre-reqs for later classes. An incredible 150 foot darkvision is eventually achieved. Immunity to fatigue, a little sneak attack damage, improved speed (from barbarian)... nothing earth shattering in the final levels, but BAB is good, Fort saves are very good, weapon specialization is accessble, the character is immune to mind affecting effects, and can actually reflect some magical attacks.
The problem with builds that rely on Ranger bonus feats is that heavy armor can't be worn. And if you have TWF or archery effects, a shield is problematic (except possibly using Shield Bash). In this build the Ranger level "unlocks" the skills needed for the Horizon Walker (otherwise Knowledge: Geography would reach 8 ranks only at level 13), provides a favored enemy bonus and lots of skill points. Track is fairly small bonus. This build requires 11 cross-class skill ranks (4 knowledge geography, 4 knowledge arcana, 3 spellcraft), or 22 skill points. An intelligence of 12 is needed for a non-human to meet the requirements, even if Ranger levels are used to purchase the pre-req's for Occult Slayer.
The "Horizon Slayer"
1. Ranger 1- Track*, Improved Initiative
2. Fighter 1- Bonus Feat
3. Fighter 2- Bonus Feat, Endurance
4. Fighter 3
5. Fighter 4- Bonus Feat
6. Horizon Walker 1- desert (immune to fatigue), General Feat
7. Occult Slayer 1
8. Occult Slayer 2
9. Occult Slayer 3- General Feat
10. Occult Slayer 4
11. Occult Slayer 5
12+ Horizon Walker- General Feat
If your Dex is 16 (or higher), use mithral Full-Plate+2 and a shield +2 instead of having +3/+3. It is cheaper, and your skill checks and saves are better.