i really like the sleepless detective, I just went into it with my PFS alchemist. I love it flavor wise.
I also like arcante trickster, and duelist.
Definitely the Magaambyan Arcanist. I really dig the whole arcane druid feel they've got going on, and I LOVE seeing arcane spellcasters (especially wizards) who don't define themselves first and foremost by that fact.
For every PC I build I look for a fitting PRC and always the same: There is non.*
The only PC I've build using a PRC was a mammoth rider but I never got the chance to play him.
It is always that the prerequisites are too obscure/don't fit or the PRC's flavour doesn't fit (we are not normally allowed to refluff much)or the mechanics don't add op.
As I am an multiclass junky taking PRCs would be perfect. But I never really got the chance to try one out.
*I am including PCs I build/planned but never got the chance to play. Because I've only ever played 3 pathfinder pcs high enough to be able to take a PCR.
There are few prestige classes I like, I honestly like the whole archetype thing better, I often feel like a prestige class takes more effort to plan for but has much the same effect as an archtype. All that being said my faborite prestige class is "Harrower" I am totally in love with this prestige class and the whole concept of fortune telling.
I know I posted here before, but I find that acceptable due to some changes in opinion. Current favourites include the Hellknight, Low Templar and Harrower, along with the Inheritor's Crusader and Champion of Irori. I'm also rather fond of the Chevalier and the Eagle Knight related Prestige Classes. However, I found myself rather disappointed with Paths of Prestige, and still find many of the Prestige Classes rather underwhelming (mostly power-wise, sometimes fluff-wise as well) and thus not really worth taking.
Two things I'd enjoy involving future Prestige Classes would be
1) Making them strong enough to actually be worth taking.
2) Letting them be setting neutral enough to be adapted to other worlds and settings.
Despite that, I had thoughts of using the Grey Gardener Prestige Class in my own campaign world of Mystralas, though I'd probably give them a more appropriate name since it doesn't exactly fit the country they'd operate in. Same goes for the Hellknights, though I might not even need to rename them since Hell works pretty much the same way in both 3.5e and in Pathfinder. There's just the problem with the more specific classes, since I don't use the Golarion pantheon in Mystralas. As for archetypes, I feel sick thinking about most of them, and find them to be a poor attempt at replicating the class kit system of 2nd edition D&D.
Since this thread is back up top again;
Grey Gardener, Tatooed Mystic and Magaambyan Arcanist.
The former just provides a character that fits the concept, well, perfectly. Between the sneak attack and bonus feat list - it gives off an impression of an absolute scoundrel whilst the judgments provide a flavour of that zealotry involved. I can see it being a sort of (failed) revolutionary vanguard element.
The latter two just provide a very unique flavour for spellcasters. Refining their options to the extent it changes how you'd play the character.
:D
And you can only pick one!
:(