You know, there is one thing about medieval fantasy RPG's that amuses me to no end.
Removing the fantasy part and simply draw from medieval europe to create a story and characters would be very original for an RPG and would make it stand out far more than any purple dragon, darkspawn, drow, orcs, dwarves, magic, massive armor designs and rediculously large weapons ever could.
A feasible scenario could be made, it could be fictional within this setting like something that could have happened.
Instead of picking a race, you would pick a country your character hails from. Based on the country you could get bonusses for weapons, skills, etc.
The english could get a bonus with longbows, Genoans could be better with crossbows, the french could be better cavalrymen, The Norse could get a bonus with axes, etc.
Of course not all englishmen where good with longbows, but the same could be said about skill bonusses in fantasy games. Not all dwarves might have skill with axes.
Eitherway, such a setting could bring together quite an interesting group as well, something that is more recognizable. An RPG does not require magic to be interesting.
Party member options could be: A Norse Viking, An english archer, a Templar Knight, A thief, a monk, A scottish clansman, A janissary, an Halberdier, A smoothtalking Italian duelist, etc.
If you throw in mounted combat, a good and enjoyable melee system, useable enviroment, bandages and sleeping in beds for recovery, no one would miss magic.
Of course the game should not be fully realistic because of gameplay purposes, a bandage could pretty much work like a health potion, otherwise your party wouldnt last long.
During the game you could also encounter some well known historical figures on the sideline.
As for the story, the crusades, the reconquista, the french-english war or any of the many wars fought in this period could be the backdrop.
Considering class variety, there could be base classes such as marksman, knight, bandit, sergeant and skirmisher.
And of course some sort of prestige classes for each of them.
marksman: Longbowman, horse archer, assasin.
Knight: Templar knight, Teutonic Knight, Hospitaller Knight.
Bandit: Pirate, thief, Rogue.
Sergeant: Guard, Man at arms, Mercenary.
Skirmisher: Assasin, Hunter, Scout.
And all of them could have their strenghts and weaknesses.
Marksman: good at range, poor at melee. Moderatly effective on horseback, depends on the weapon being used.
Knight: powerfull on horseback, diciplined and educated. Weak with ranged weapons but can inspire others with leadership.
Bandit: versatile and shady character. They are good at making threats, scavenging weapons and armor and fight dirty.
Sargeant. A common soldier. While most profficient with melee weapons such as spears, axes and swords, they are less skilled in the use of swords than knights and have a bit less dicipline and are not such great riders as knights. However they are far more capable at using spears and halberds than knights, and can perform tasks knights would consider to be beneath them such as digging and some light blacksmith work.
skirmisher. Kind of a crossover between a bandit and an archer. They are more capable in melee than archers and are more profficient with throwing spears than any other class. They know how to use the terrain to their advantage and can lay ambushes and create traps. They move quite fast on foot. In melee they are quite weak when not on the offensive however, and their range with ranged weapons is less than that of marksmen.