We know that a Civ game takes a hefty long time to complete, especially in the late game with 60+ cities and 100s of units to manage, each turn takes an hour. I have a suggestion - it's sort of radical for Civ, but it's taken from other games like Homeworld where you play these single episodes that usally take a 1/2 hour to 3 hrs to complete. Once done, you have a sense of accomplishment but you can continue to the next episode with all the same stuff you had remaining from the last one. In homeworld, these would be the hyperspace jumps.

In this 'radical' new Civ game, it would be the lifetime of a ruler. Now wait, before you trash this, consider, what if we had a civ game from 1000BC to 2000AD - this would leave about 60 episodes if we assume each ruler's lifetime is approx 50 years. (Give each ruler at least 100-200 turns though to shape their civ, therefore 1 turn =1 season or 1/2 yr).

Ok, advantages are:
1) Viable ancient battles, it's not just a race to howies
2) allows time to recreate such empires like ancient babylon and persia that aren't possible in an ordinary civ game
3) Linear timescale allows realistic movement
4) Timescale that is familiar to human experience (we know what it's like to do something for decades, not centuries)
5) Adds the strategy of choosing successors and worrying about after-death stability of empire (this was the primary concern of most monarchs, and is still important to people today)
6) more submersion into the "atmosphere" of the game and era
7) allows generational and age to be modelled
8) allows turn-by-turn tactical play and episode by episode strategic play
9) local random generator lets you start a game in any episode

Disadvantages:
It would still be really long to complete the whole game, even with breaking it up into episodes. I imagine it might even take up to a year to play a full game! But you could consider instead each episode a separate game.

In my opinion thats a great idea. Although I confess to being a little biased on this topic. When Apolyton was putting together its Civ list, I put together my own with a HUGE number of suggestions! One of the ideas I put forward was to break the game up into "Episodes" (Namely: Ancient, Classical, Medieval, Renaissance, Industrial and Modern). My idea was to set an end-chapter task for each section of the game (most likely a specific level of advancement in each scientific field), at which point the chapter would end. You could then choose to go onto the next section or save the game. My other idea was to allow players to start the game at any chapter (eg. a game starting at medieval instead of Ancient)starting with a default number of cities and advancements, or using a previously saved game. My final suggestion was to allow the awarding of points at the end of each chapter (sort of like in scenarios), based upon certain victory criteria. You could then use these points in future chapters to customize your civ with appropriate special abilities or to purcase great leaders.
My main argument for this approach was exactly the same as yours! (Great minds think alike!!) Anyway, thankyou for showing me I wasn't alone (and who knows, it might be in the game-but don't hold your breath)

If Firaxis would allow us to link scenarios together, than an organised effort could produce something as big as this, this would have to be 60 scenarios linked together!!! It would be amazing if such a project could be completed. And would probably take a year at least to do so with 60 people involved...

Russian King:
Yes, I know it sounds strange and it seems like a huge effort, but I didn say I wasn't expecting it to be civ 3, or even civ 4 or a descendent but it is along the same lines. who knows, maybe some day in some other game.

Erka:
True, it would take a long time to play all 60 episodes - but not undoable. I think Starcraft had 30 episodes and while the first ones took 1/2 hr to 1 hr, the late game ones took 3-6 hrs. Still I know many people who finished the whole game within 1-2 weeks.
Besides, in this system, each episode is like a mini-game. With Aussie Lurker's ideas about points/victory conditions, you wouldn't feel like you were cut off at the end of an episode.

OneFootinthegrave:
I don't just mean linking scenarios, though that would be very very cool. What I mean is that the next episode can be continued "as is", as you left off, you inherit the kingdom from your previous episode's ruler.
Then, there's also the option of a random generator (with user specififed variables like #cities, tech level, etc...) that allows you to start at any episode. And the episodes aren't necessarily preset for a certain length or year.

Anyone have any other ideas to contribute to this? Your suggestions are most welcome!