As a GTA fan, I was overly surprised...Saints Row is simply insane!
Gameplay: Less complicated than GTAIV, but just as fun as Just Cause 2. The biggest upside is the smooth fluidity of combat. Gunplay is easy and fun, and the explosions leave you smiling without notice. Thumbs up in this topic.
Story: It is your typical gangster, heist, criminal mastermind personas that flow through the game. But you'll definitely be left laughing at times at some of the satirical remarks from all characters. Good humor if your into that stuff, I know I am.
Graphics: This is where Saints Row could have nailed a 9+ from me, but it just falls a bit short. I'm not sure if it is the engine, but its definitely not my rig. I can run Crysis 2 on Hardcore with 30-40 fps, but hardly run Saints on Max with 30fps. The optimization could have been a bit better, who knows.
Multiplayer: Co-Op and "Whored-Mode" multiplayer adds some flexibility to the game inbetween the awesome single-player. Its just plain silliness. But just shy of being better than GTAIV's quick cellphone multiplayer match-up that got me hooked.
Overall, I really enjoy this game, and currently 55% completion, still craving more. Its an awesome game and I'm considering picking up the previous Saints just to fill my cup of enjoyment. Happy shooting!