It's funny to see this thread topic here - yesterday I posted in a thread of the same topic on the GiantITP forum.
Currently one of my favorite 'dream concepts' is a dwarf Hammer of Moradin, a cleric/fighter who's gone out into the world to smite the enemies of Moradin. I just really want to use that PrC's 'quake' special ability, and the returning hammer ability. Yeah, sometimes I'm a munchkin.
A spirit folk shaman - not the spirit shaman, but the Oriental Adventures shaman. Spirit shaman sounds like it would be perfect for spirit folk (the Forgotten Realms spirit folk, not the OA ones), but the description in both FR and OA says they're not interested in trying to manipulate the spirit realm. Since they seem to come from a sort of mystical tribal culture the OA shaman seems better suited to that race.
A wizard from a different culture than whatever culture is prevalent in the campaign, using the wu jen class to simulate a different type of magical learning. Then take that wu jen into the Elemental Savant PrC.
A gnome beguiler in the Eberron setting. It just seems like a perfect match of race, class, and setting. The gnome would use the beguiler's abilities to manipulate others into acting for the greater good, since I don't like playing evil characters. She might have learned the Zilargo gnome ways of secrecy but she doesn't really like them. Yet she can't change her nature or her upbringing.
A shifter ranger who was raised by wolves.
A half-drow ranger or druid who was adopted by a kindly druid and raised in isolation in the wilderness, so the prejudice against drow comes as a horrible shock to her.
In a campaign I'm currently in the PCs were all indirectly brought together by a paladin of Lathander, so there's a continiung thread of 'new beginnings' running through the game. In the course of the campaign we've met a tiefling NPC who was offered a 'new beginning' by the paladin, and had a PC in the party who was once a sort of mob enforcer but decided to pursue a new beginning by joining our group. Should my current character ever be lost, I'm always thinking of what I'd want to play in his stead; I've imagined using the half-drow concept in this campaign, as well as a genasi streetfighter character.
An elf paladin. I love playing elves and I've never run a paladin.
A cleric of Kelemvor dedicated to destroying undead and bringing peaceful passage to the afterlife to every dying person she encounters. She'd have to stop in every farm and village to minister to the dying, and she'd always want to coup-de-gras her enemies so they wouldn't suffer.
I have tons more - I'd better stop now.