I would like to see a Might and Magic RPG. While seen in the first perspective, you actually control a "party of people". Eight is usually more fun.
There are two really fun things about this type of game.
First is character creation and development. Choose from human, dwarf, gnome, half-orc, elf etc. Choose their role - thief, barbarian, knight, archer, sorcerer, cleric etc. Choose male or female. The enjoyable bit is when you DON'T see the characters so that you can imagine your favourite book/movie characters in the role (though I guess you could use jpgs from the net for portraits).
The fun comes in upgrading those characters - gaining experience points by fighting/solving quests. This gives increased points to body, mind, quickness, strength etc etc allowing you to travel to more dangerous parts.
Barbarians get a large number of points to body, those that can do magic get the least (hence position them at the back of the party) - but they get new deadly spells.
Its also great fun getting money and weapons from things you've defeated as you kit out your characters in different bits of armour, weapons, rings with special powers.
The whole thing revolves around choosing which characters you want in your party (all warriors, lots of magaicians, mixed?) and building those characters up - eventually getting lots of strength, spells, and cool equipment (buy items in towns etc).
The second fun aspects is that its not like a first person shooter where you have to do things in certain orders. In the old M&M games you had a vast world to explorer (a "block" area of the world would load at a time).
You were not restricted at all - though if things proved too tough you'd need to run away quick! Exploring was great fun - especially on one of the later games where you started off owning a castle which you could explorer. Rope bridges in the mountains, cold ice fields, pleasent towns, elf towns up in the trees, indoor areas (castles, caves, dungeons and a huge dwarf world all underground) proved fun.
