
BENSLAYER |

This is almost totally copy/pasted from my own list and so crosses over with many already said :
* Bard(Hoaxer) -> Common and Major Hexes (restricted).
* Cleric(Divine Scourge) -> Common and Major Hexes (restricted).
* Inquisitor (Hexenhammer) -> Four Hexes (pseudo-five).
* Magus(Hexcrafter) -> Up to 2 Common Hexes, 2 Major Hexes and 1 Grand Hex.
* Mesmerist(Dreamstalker) -> Slumber Hex.
* Oracle(Spirit Guide) -> Single Hex.
* Rogue(Sylvan Trickster) -> Same progression as Witch bar Level 1 Hex, (more versatile as can chooses either a Hex+ or a Rogue Talent).
* Summoner(Spirit Summoner) -> Four Shaman Hexes -> Witch Hex option.
* Vigilante(Serial Killer) -> Charm Hex (restricted to non-Animals).
N.B.: Spiritualist(Involutionist) -> Four Shaman Spirit/Phantom(?) Hexes; Wizard(Spirit Whisperer) -> Three Shaman Spirit Hexes.

MrCharisma |

* Magus(Hexcrafter) -> Up to 2 Common Hexes, 2 Major Hexes and 1 Grand Hex.
That's 5 hexes total.
The "Hex Arcana" class feature potentially gets you hexes at levels 6, 9, 12, 15 and 18 (that's 5 hexes). The "Hex Magus" class feature gives you 1 free hex (we're up to 6 hexes). Also I can't think why you couldn't take the "Extra Arcana" feat and grab another 8 hexes if you want to (all normal feats from level 5 up).
If you disagree with Extra Arcana working you should still end up with 3 hexes, 2 major hexes and 1 grand hex.
EDIT: I didn't mean to sound so dismissive. That was a very comprehenwive list, so thank you. Also I can't comment on the other classes because I don't know them as well.

shadowskinC |
The stargazer prestige class gives you a witch hex on level 1 and 9, with lots of other good stuff like priest domain,familiar,2 initiate bonus & no flat footed before your turn. Though the bonus hexes scale only with stargazer level(provided you're not a witch), so it's bit of hard to find a good hex as a wizard(N)+stargazer(3).

Joynt Jezebel |

I have never seen a Sylvan trickster being played but they are actually really good. And the into to the archetype starts-
"Sylvan tricksters are rogues who model themselves after the mischievous fey of legend. Though not spellcasters, sylvan tricksters learn minor magical abilities reminiscent of those favored by fey creatures."
Who wrote this. What sort of twerp thinks witch hexes are "minor magical abilities".
And the rogue, magus and maybe other archetypes mentioned here can get use out of -
"Hex Strike (Combat)
Chanting and cursing, you put a hex on your enemy as part of your unarmed strike.
Prerequisite: Hex class feature, Improved Unarmed Strike.
Benefit: When you gain this feat, choose one hex that you can use to affect no more than one opponent. If you make a successful unarmed strike against an opponent, in addition to dealing your unarmed strike damage, you can use a swift action to deliver the effects of the chosen hex to that opponent. Doing so does not provoke attacks of opportunity.
Special: You can take this feat multiple times. Each time you take it, you apply it to a different qualifying hex."
Take a race with an innate attack and this feat, with slumber as the hex. Precision strike them, do a ton of damage and then they save or take a snooze.
Hex strike is useless to a witch as you need to be next to an enemy and then hit them. Not good for a squishy witch which can't hit anything in melee anyway.

MrCharisma |

Hex strike is useless to a witch as you need to be next to an enemy and then hit them. Not good for a squishy witch which can't hit anything in melee anyway.
You can use the PREHENSILE HAIR hex and the FERAL COMBAT TRAINING feat to avoid being next to them.

ShroudedInLight |

I had a game for folks at a higher level that had a Hexcrafter Magus show up with: Improved Unarmed Strike, Weapon Focus Hair, Feral Combat Training, Hex Strike, Prehensile Hair, Accursed Strike, and Natural Spell Combat. That took 4 feats and 3 magus arcana, got it done by level 7 as a human with 5 feats (in order to cheat out a Hex under the interpretation that extra arcana would allow you to trade for a hex). As the game started at level 9, it still left him some goodies to play with.
His "wombo combo" was to activate his burly mustache (His mustache grew into a pair of biceps that constantly flexed) and Spellstrike a Bestow Curse (-4 to Will Saves) into Hexstrike with Slumber. I think he also took Evil Eye for more Save destruction.
Its worth noting that no matter what order of operations the GM rules for spellstrike/hex strike you win. If the hex happens first then you use it to Evil Eye and lower their saves for your spell, if the spell happens first you Bestow Curse and use it to lower their saves for the hex.

avr |

On the subject of 'witches have no use for hex strike' consider the Ashiftah witch archetype. From 2nd they can turn invisible (as per Vanish, but a Supernatural ability) as a move action after using a hex. Use a hex normally the first round to start it off, then punch people and follow with hex strike and vanish again as often as you can afterwards. Once you have the spells to burn, touch attack spells delivered via unarmed strike can add more to the combo. Note that while casting spells disrupts holding the charge on touch spells using Su abilities doesn't.
A level dip in some form of monk or similar (maybe one of the unarmed magi archetypes?) would be useful but not essential. Or the Ashiftah witch could be the 2 level dip in some other build, maybe a rogue-based one.

Joynt Jezebel |

You are perfectly correct avr.
For some reason the Astifah Archetype is absent from d20pfsrd and I have never seen it before. It is very good indeed.
That ghostwalk ability is wondrous, the ability to keep using vanish on yourself as a move action after casting a hex and then take a 5 foot step. No limit on the times per day. If only you could combine it with cackling it would be perfect.
I suspect the best, meaning most powerful, option if using the Astifah/ Touch attack combo is to be just the Astifah Witch but a race with a natural attack.