The Guitar Hero for the Guitar Heroes.
If you don't know how Guitar Hero works, then that must of been a pretty comfy rock you were under. You have a highway of notes that come at you, you strum or hit a pad or sing when they cross the bar, and you score points. You can gain star power by hitting certain phrases, you have a rock meter which tells how well your doing, which will go into red if you miss too many notes and will cause you to fail...you get the idea.
Guitar Hero: Metallica is, in my opinion, the best Guitar Hero since Harmonix abandoned the series to start working on Rock Band. The soundtrack is what makes the game such a success, as Metallica is what people consider to be one of the greatest metal bands of all time. The songs (not only the one by Metallica) are fun, challenging, and are good songs to listen to if you like metal.
One of the key editions to the game was the addition of Expert + for drummers, which allows them to use 2 drum pedals to play songs. This where Guitar Hero: Metallica shows what it really is - a hardcore game for hardcore players. Expert plus is INSANE, and the song One, which was considered the 2nd or 3rd hardest song in Guitar Hero 3, is easily outside of the Top 5.
However, there are several flaws in the game. Singing is still overly difficult, which can be frustrating when your going for some of the vocal achievements. Speaking of achievements, it is my personal objection that there is an achievement for completing all the turtorials, and then the games says you need the official Guitar Hero drum controller to do the drum controller (WTF!). Also, there is no online band career or online band quickplay with less than a full band.
Despite these complaints, Guitar Hero: Metallica is one of the best Guitar Hero experiences available right now. In my opinion, it does not top Rock Band 2, but is still worth the attention of fans of the series. And now, only one question remains - where is Ride the Lightning?