Age of Empires: Several resources that must be found, mined, gathered and dropped off.
Key elements: Drop off building, gatherer, mine, resource

Starcraft: one resources that must be found, mined, gathered and dropped off.
Key elements: Drop off building, gatherer, mine, resource

Command and conquer:One resource one means of harvesting.
key elements: Tyberium, drop off building, harvester.

Supreme commander: two resources, one player generated and one map resource. No gathering, no drop off buildings. Build-and-forget.
Key Elements: Mass extractor, mass deposit, generator.

Dawn of War: two resources, one player generated and one based on capturing map locations.
Key Elements: Infantry, requsistion locations, plasma generator/slag

Universe at war: Earth Assault: Different resource for all races, some collect bodies some consume props around them for resources.
Key elements: Every prop/unit in the game has to be a resource.

Call to War: The map is your resource, build anywhere for a base resource rate or use an ability to find hotspost. Randomly generated resource grid invisble to player that has cool spots around bases and hot spots the farther out you go.
key Elements: resource center

Humm, I don't really know what system i like the most, The AoE in is kinda good but they have a tad to many resources. But what i like is that you have to keep the supply lines running, It gives your enemy a strategic target and you someting that you need to defend (same goes for Starcraft (I think) and C&C).

I Also like the DoW system since it's that mix of player generated and map strategic system. It doesn't give your enemy any supply lines to cut but instead forces him to attack Outposts in order to cut the supply.

Hard choice, I'll have o think a tad more before I vote

personaly i favor the aoe style of resources. i like accually feeling like i am building my base out of materials from the map. and it would make sense that you would need more than one type of material to make a building, or whatever else.

damn wrong voice, AoE i mean and Universe at War

Definitly dawn of War
I like how they consider tactical points as a resource.
I like how it emphasizes controlling terrain as a strategic element.

I'm a fan of Dawn of War, Starcraft, and Supreme Commanders resource gathering systems (and Dark Reign, well most of it). They all suit the scale and goals of those games.

For Warcry I would say a resource system similar to Starcraft or DoW would be appropriate,due to the games similar scale. My personal suggestion is to have a 2 resource system, one on the map the other player generated.

The map resource would be mined like in Starcraft but using fewer resource collectors. this has a threefold benifit over SC: units don't get in the way, the poly count wasted on collector units is kept down, and it lets players focus on building other units instead of a stream of collectors. By having more resources in other area's of the map you also encourage exploration and expansion similar to what requisition does in DoW.
The player resource would be Power. You would simply build power generators in your base and they would provide a steady income of power. Power would be used to keep buildings and the minimap operational (perhaps a steady decrease in the power gathered per second), and vehicles and other higher tech units would require a one shot consumption of power to be built (the same way power in DoW and vespene in SC is used).

Having only one resource in the game severly limits the flexibility of unit and upgrade costs, while having too many takes the focus from combat away and more on intensive resource management. The two resource system seems to be the sweet spot, and most of my favourite games follow that formula, including all the competitive ones I know of.