In terms of being a fan of the series, you can not go wrong with this game. It is by far the best in the series (although others would argue MGS1 to be better in terms of story).
+ Excellent graphics
+ Excellent sound
+ Excellent replayability (Emblems, unlockables)
+ Unrivalled in almost every area
- Really long cutscenes
The reason I have put the cutscenes as a con is for people who are new to the game and series in general. People who are used to FPS games which are generally all action and next to no watching may think this is a shooter when really it's more of a "Do not be seen at all costs!" game.
However the option is there to be all guns blazing and there is a fantastic array of weapons that can be found in the game. A lot of which are customisable to a huge extent (grips, laser sight, grenade launcher, suppressor, you name it).
After completing the story several times over (once is not enough trust me!) you can move straight on to MGO which is basically taking everything from the single player and making it an online game. You do have to go through a registration process at Konami online but it should not take you too long and you will be set up and ready to show off your skills.
Control scheme for this game has been more westernised and is played mainly in 3rd person with the option of going to first person (although it's only really useful if you want a precision long range shot). It can be difficult at first if you are not used to 3rd person shooters but after a while it becomes natural and you do not really need to think about it.
Overall this game is one of the best games I have ever owned. Anyone who owns a PS3 and does not own this is missing out!