A decent compilation for newer C&C fans, but there's little reason for veterans to purchase it.
The First Decade includes Command & Conquer, its mission disc Covert Operations, Red Alert, its mission discs Counterstrike and Aftermath, Tiberian Sun, its expansion Firestorm, Red Alert 2, its expansion Yuri's Revenge, Renegade, and Generals along with its expansion Zero Hour all on one DVD. For the most part the games work fine under Windows XP, but there are some very significant bugs out of the box.
The largest of the bugs is the lack of Soviet movies in Red Alert 1, and the lack of music added by the C&C and Red Alert mission discs. There were two patches that fixed these major problems, but you need to install both patches separately as 1.02 does not contain the fixes from 1.01.
The First Decade comes with some bonus features, but they're not really worth watching since they don't offer any useful insight into any of the games in the compilation except Generals.
If you want to install all of the games included in the compilation you need a lot of hard drive space, as everything including the movies is installed. The First Decade takes up 10 GB if you install all games, not counting saved games and mods so make sure you have plenty of hard drive space left over.
Is The First Decade worth it? Only if you're a newer C&C fan who wants to play the older games. Veterans who already own most if not all of the games in the package do not really have any reason to buy this compilation. Still, the C&C games are excellent so it's a great deal for the newer C&C fans, and the future C&C fans who get into the series with C&C 3... just remember to download both patches.