A bargain-bin steal (at $3!), with some big flaws, but some interesting concepts.

User Rating: 7.8 | Total Annihilation: Kingdoms PC
This is NOT the greatest RTS of all time; in fact, it's not even close. It is, however, a very fun game nonetheless.
First, the bad: for today's standards, the graphics aren't that great. What was "WOW" in 1999 is just blocky and coarse in 2007. Also, sound effects are somewhat irritating (battles are announced by a high-pitched gong that, if you're not braced for it, will make you leap out of your chair).
Balance is nonexistent: only two races (Aramon and Taros) have even a nodding equality with each other. Zhon is badly over-matched in power (though they do have a good hit and run force), and Veruna only makes sense on a naval map.
"You've basically torn the game apart, reviewer! Why give it the score you did?"
Two words: it's FUN.
The single-player campaign uses a very unique mechanic (switching viewpoints between the 4 factions) to tell a compelling story of fratricide and civil war that lasts close to 30 chapters. The climax is a good vs. evil battle that could take hours to beat.
In short, I got more than my 3 dollars worth out of this game, and (at that price) I can say that I recommend it, even with all its flaws.