Wackiest game ever is also one of the best.
Okay, now that you know that, lets split the game into different sections: Gameplay, Graphics + Sound, Story, and Replay Value
GAMEPLAY: Expect GTA-type gameplay with all kinds of zany twists (read the intro paragraph). Controls are great, although a bit different then Saints Row 2. Since I was used to Saints Row 2 controls, it took a few missions to get used to driving controls changing, as well as sprinting. Other than that, I like the new control scheme. Bugs pop up relatively frequently, mainly when you or a homie is getting into a car. But overall, I think anyone who plays it will have a good time playing it.
GRAPHICS + SOUND: The graphics are not as top-notch as I was hoping for, but the vivid colors look great. This is one of the most colorful current-gen games. The liscensed soundtrack is great. It is amazing how varied the soundtrack is - it ranges from hip hop to alternative to screamo to Beethoven, however a few times during shoot-outs in the game, a hip hop song played and it can not be stopped. I wouldnt mind it if it was an okay song, but it wasnt my style of hip-hop, it was the style that says the N-word every five seconds. I would've liked to be able to change it to a soft-rock song I can enjoy clearing out buildings to. Voice acting isn't anything special, though it did do a good job of making the characters sound like real-life gangsters.
STORY: Story is great, however free-roaming is even better. The story is about 25 hours long (or at least thats what it took me) and each act (there are 3 - they contain about 15 missions each) has 2 possible endings, and each awards you with an achivement. Anyone who though Saint's Row 2's story was boring will definitely change their mind when they play Saints Row The Third. (WARNING: This paragraph contains spoilers) There is a segment that takes place in a computer world, and also a potential ending of the game takes place on Mars. (Spoilers end). Thanks to SR3's wackiness, the story is much more interesting then other gangster games such as GTA4 or Mafia II. However, you will spend most of your time as a free roamer, wether you are completeing activites and diversions or just starting random fights with cops and enemy gangs.
REPLAY VALUE: Personally, I have already spent countless hours with this game, and I doubt I will ever get bored of it. I have played through the game twice to unlock all the story-related achievements, done tons of the activities, and I still have a ton to go. Just when you think you've fully completed everything, another thing comes up. The insanely high replay value makes for you paying way more than your money's worth.