I have recently been playing Rise of Nations a game by Big Huge Games. I must say that in a genre that's nearly as overcrowded as console RPGs it's managed to have very innovative and unique gameplay. From having defined borders, to attrition damage, to handling diplomacy with computers, to having resources as a limited rate rather than a finite amount it feels very unique and well put together.

Here are some things that really set it over the top.

Plot - There is none other than you're a leader of a nation out for world domination. No interludes, CG sequences, dialog sequences, or anything to interupt the great gameplay.

Graphics - It's a 2D game in a time when everything seems to be 3D just because it can be. The 2D graphics style fits the gameplay well and keeps out the technical and visual issues that 3D games have. It looks great with no blocky polygons or anything like that. Well the units are rendered but the lack of camera control prevents you from being able to tell.

Gameplay - The interface is well done and you'll never find yourself micromanaging for too long. Your citizens will automatically find work to do. If there aren't enough people mining a resource they'll automatically go and work, if a building is unfinished they'll go to finish it, if a building needs repair they'll repair. But if you really want to micromanage you can disable the automatic workers and cycle through all the slackers with the period key or you can select all the slackers by holding shift then hitting period. Need to research something? You just have to hit the Tab key to cycle through all the buildings that have technology you can research that way you don't need to leave the area you're currently focused on. This makes it very simple and quick to manage your cities so you can get to the important parts like trashing your enemies! Rather than having resource nodes with a set amount of resouces you just have limitations on how quickly you can gather resources that way once you have set up a mining camp you don't need to constantly worry about relocating your workers but you're still limited by the fact that you can only get so much at a time so you can't just go on a spending spree with no regards for money. The game also handles people who like to wall themselves behind miles of attacking buildings as well. Everything you buy of the same type has its price increase so you can build a lot of defensive buildings but it gets quite costly to cover a large base. This also applys to units so it may be more effective to use smaller groups with a variety of units and buy more as your quantity of them dwindles(since the price also drops as you have less of a certain building or unit).
The conquer the world campaign is also great. It's kinda like risk. You take turns moving your armies across a world map collecting supplies, cards, and territory on a board game looking like board. Then instead of rolling dice to determines who gets the territory you fight it out in an RTS battle. The defender usually must hold the land for 90 minutes(or wipe out the opposing army) to mantain the land or they lose it. You can also use various cards and special resources from other parts of the world to aid in your defense or offense for the land.
All in all this game feels a lot different than any other RTS game while still keeping the basic concepts that make it an RTS.

AI - The AI seems pretty good at playing the game without resorting to massive cheating(ie Empire Earth) or cheating at all unless you play on the hardest difficulty.

Tutorial - Luckily it's optional and its set up very well since you don't have to do the whole thing to learn how to do a few things. Its divided into several sections so you can pick up on only the stuff you don't know about.

Multiplayer - I havn't played yet multiplayer but it seems that you can only play skirmish type games(ie the standard RTS macthes). It's a shame you can't play the conquer the world mode multiplayer as it would be awsome even if it took a long time to finish.

Anyway this is a great game even good enough to deprive me of sleep which hasn't happened since I got Avernum 3 which was about a year ago. So if you're into RTS games you should probably check out the demo over at http://www.riseofnations.com . You can play an entire skirmish game against the computers with no limitations on the technology you can research or the units you can use. The only big things missing in the demo is the Conquer the World campaign or multiplayer modes.