I would personally like a long quest, kind of like Quel'delar.
The quest in a nutshell could be about you finding a Sacred Book of some sorts in a raid boss, you bring it to Northshire for information, you find out it is of great value without really getting to the part where they explain "why" it is.
You've been followed all the time, blah, blah, consequently the place is attacked and the guy you gave it to has been kidnapped or something.
You quest your way thru a phased Elwynn Forest undertand wtf is going on and to rescue him, etc.
The main bad guys in the story could be the Scarlet Onslaught, at the end of that quest you manage to free your quest giver and engage a boss based on your Role of choice (slightly harder than Proving Grounds Gold) after you succeed, your quest giver (we'll call him Bob) will tell you they took the Book and that it's importance lies in what is inside, having part of a Naaru within.
To show his gratitude for your aid he rewards you with knowledge to improve your Charger, allowing it to fly.
Now you and Bob return to Northshire and are basically tasked with retrieving the Tome.
You and him (which will serve as your Tank, Healer, or DPS depending on your role) go thru many scenarios that explain in detail the lore behind Paladins, how the Scarlets came to be and tie up the loose ends of WotLK Onslaught.
Culminating in taking out Bad Guy Number 2 at the end of what was a phased, Scarlet Infested Stratholme (that is hopefully not burning anymore).
You do get your hands back on the Tome and hand it over to Bob but he's bitch like this shit is empty (ok maybe not quite like that), and it no longer contains that essence sealed inside... though in itself this tome is worthless, it feels pure and blessed.
Excuses to makes you some shit out of it.
Once completed you're awarded a Libram of your choice (out of 3) which displays on the side of your Hip as long as you carry one in your bags, you can buy the remaining ones from Bob in Northshire at the end of the whole quest.
Libram of Sanctity: Beige Tome with Golden Glow, ribbon and details. - Pulsates a Yellow/Gold Crusader Aura under your feet.
Libram of Devotion: Silver Tome, with Blue Glow, ribbon and details - Pulsates Blue Devotion Aura under your feet.
Libram of Retribution: Dark-Grey Tome with Crimson glow, ribbon and details - Pulsates Red/Orange Retribution Aura under your feet.
The final part of the quest takes you and some of the Knights of the Silver Hand chasing after the essence, which will be used creatively by a meanie old face (Final Bad Guy) to grant himself power... fluctuating Light and Dark powers... to destroy all the infidels! >.>
Blah blah, this Boss in essence would be as hard as Kanrethad himself to do.
In the end he dies, for your service and devotion you're admitted in their ranks and bestow a title upon you (of the Silver Hand / Blood Knight / Sunwalker).
Where the boss had fallen lays a shard, glowing with a dim light.
The council takes possession of it, and though it's essence is weak, to thank you for your efforts, they decide to forge a weapon out of it for you.. a cosmetic Ashbringer.
Yeah, maybe it's too many rewards, yeah I wrote the alliance side only, I'm bored, but not that much.