What a game this is. Definitely recommended to fans of open world games such as GTA or Saints Row. I really loved everything about this game and it came as a big surprise. I wasn't even planning on buying it, but someone offered me a trade for my DS (which I NEVER used) and I'm really glad I decided to take it. The story and voice acting is top notch and the game is quite impressive visually. It might not be the most original game (borrows a lot from other sandbox titles), but who cares when you're having this much fun.
The fighting system is really the stand out feature here, IMO it is even better than that of the Batman games. It works almost the same and while Batman's is a bit more fluid, I really like how you can interact with almost anything in the environment during a fight in Sleeping Dogs. Even if something doesn't have a specific kill animation you can still use it to help you beat up your enemies. E.g. if you're close to a railing you can throw people over it or if you see a table you can smash someone's head against it. Soundtrack is also pretty good, especially the Roadrunner Records radio station. Loved driving around Hong Kong listening to Fear Factory, Devildriver, Killswitch Engage, etc. Finished the game last night, but I'm gonna spend some more time with it to finish up the sidequests, races, etc. and to try and get more of the collectibles so I can max out my character.