please feel free to question, adjust, and add to this.

A. cities have a core area for business/residential areas and a resource area that grows over time. hopefully cites won't be limited to 2 squares of
L shaped territory. example, i build a city by the sea/plains for easy trade/early growth. later on though the city will overgrow its old source of food and probably rely more on the sea(around middle ages) but it would also expand and seek out nearby hills/mountains/forests for resources.

B. general level advancements. it's quite annoying and unrealistic to be in the nuclear age or beyond in civ, and have neighbors that you activily trade with or are just next door to that are so unrealisticly
behind you technically(and in other areas). you still want certain nations/cultures to be able to get really high advanced in certain areas while being relatively dumb/behind in others! example, maybe allowing a country to keep it's monarchy/depotism well into modern times.

C. ability to build more than one thing at a time. cities should have different production cabilities. for example, i could build a tank since i have military/civilians factories/skilled people to do so while my civilian construction works on a new library.
not all cities should have the people/resources/factories to build all things!

D. more detail. the civ1/civ2 and even smac maps are small and not very detailed. you need to include more terrain/mixed terrain types. look to colonization for some ideas!!

E. more cultures. i want the huns, the celts, the apache, the swedes, the cretetians, the gauls, the turks, and etc...!! they also need to differ from one and another. example, the english loved their longbows for a long time while the turks and others were trying out gunpowder. example, the germans during ww2 thought they were superior, while the americans were pursuing equality in the coming decades.

F. while already mentioned(civ team answers) i hope every possible leader is included mendela, stalin, lenin, FDR, greronimo, ghandi, mao tse tong, malcom x, and etc... should all have the potential to have controllable groups within cities/nations or maybe even new cultures from themselves a possibility.

G. more history into civ3. you should progress through eras. you need civil wars, revoultions, colonial era, reniassance era, sea going pirates,
hostile indians/natives, ability to harvest the moon/mars/etc, the cold war, vietnam and all the other things that different cultures have gone through.
of course the game could deviate from these histories but you should be able to play the game historically. add some new things too(surpirse us!), just because things didn't happen in our history(or haven't yet) doesn't mean they shouldn't be possible in civ3.

H. separate ai's(maybe even people?) that control
organizations/companies/cultures that operate independantly and respond to various happenings caused by both you and the computer players. this i think
is the key to making the ultimate civ game!

just the above which i came up quite quickly is a lot of work and extremely hard to inculde in a game(the research alone is staggering) but if included all these things along the firaxis spin and other ideas i know it'll be a product that will be far above and beyond even most civ fans imaginations.

btw, please get rid of pollution!

I am in a hurry, so I couldn't read all your suggestions. But I just want to say that when you post your new suggestions, post them in several seperate threads, so we dont get confused, and so we can discuss one topic at a time.

As Diablo already kindly stated please seperate your ideas into seperate posts in the future.

Your ideas are intruiging, but most if not all have been discussed in great length. Please take a look at Related Threads for some of the major discussions that have taken place.