Wow, thanks for the awesome compliment commander!
As a matter of fact, I had never even thought of standalone buildings, great idea! Do you have something in mind?
You're welcome. It's well deserved.
As for individual buildings, one good start is to give each resource it's own type of building that makes it more valuable. Something like, if a city has X resource in it's borders, it can build said structure to make that resource more valuable. If you're able to make a building chain to mark the progress of human innovation and technology, even better.
Listing off a few off the top of my head:
Wheat:
Bakery and/or Brewery. Adds extra food/happiness for the cities in which they're built. Obviously, you'd need wheat within a city's borders to allow this structure to be built within the city. Both buildings should be available extremely early on, noting how commercially available beer and bread supplied food for the citizenry that worked other professions.
Fish:
Fish Market -> Cannery. Adds significant food to said city in which it's built. Maybe even add a production bonus for the cannery, to represent the rise of how preservatives and sealed cans/jars/bags has impacted our lives. No longer do we need to go to the market every day just to have a tuna sandwich.
Cattle/Deer/Sheep:
Butchery --> Meat Packing District. Same general idea involving the fish market/cannery line. Pretty self explanatory as to how these buildings have impacted the lives of humanity through the centuries. Adds food and production bonus
Cotton/Silk/Dyes:
Weavery --> Textile Mill Adds wealth and production in the city they're built.
Gold/Silver/Gems/Pearls:
Jewelers. I know the mint can use gold/silver already, and it'd probably be the framework you'd base any of these building ideas on, but yeah. Having something to supply your population with valuable luxury goods. Tell me the last time you just bought the diamond without a ring or a necklace for your wife/girlfriend? Exactly, lol. Significant wealth growth.
Oil:
Plastics Plant The Plastics Plant would be a late game addition (Modern Era) to the game. Adds a huge wealth bonus to the city as it shows the sheer demand and diversity of plastic products in our modern society.
Oil Refinery. Industrial era building that adds a significant boost to production, and speeds up the creation of any unit that requires oil.
For some non-resource based buildings, let's see...
Sewer system: Adds a big happiness boost to a city, as people don't have to waddle through rivers of human waste on their way to work. Industrial era building for cities.
Town Square ---> City Hall. Removes a small portion of city upkeep and adds a slight increase in wealth generation to the city. The chain would work based on the population of the city, so once a city hits...6 population, the City Hall would unlock to add a higher bonus. Having a centralized meeting place where your people can address grievances and deal with government/administrative issues makes your people have an easier time paying fees and taxes (boost in wealth generation) while giving a centralized location for your civil servants to operate (decrease in city upkeep).
Basically that's all I can think of now. I'm sure people have hundreds, if not thousands of other ideas you can ponder. Hopefully a few of these sparks some interest in you