lordlillen said:
metal gear solid 4 enough said
Not really enough, as while some great cutscenes were in it, my favorite moment took place during a gameplay cutscene. Alternatively, the statement you're implying could be the over abundance of cutscenes to be a negative. Enough said is hardly the thing to say about Metal Gear or Xenosaga when it comes to the question of cutscenes' worth.
ANYWAYS, it depends both on the game and on how the cutscene is handled.
If you're focusing on immersion solely (like say Fallout 3), you'd want to stay away from them, unless you decide that a "set piece" is a cutscene. It's not that a cutscene would automatically mean the immersion is broken, as if it were a horror game and in the scene you're put in a second person perspective for a moment to indicate something is watching you, then in a third person perspective in which your character is oblivious to that thing coming down gently from the ceiling, where every fiber of your body is screaming for them to look behind, and then the scene ends with either the creature attacking or disappearing as soon as you notice it, the feeling is kept.
Now the big thing you want to avoid is making it so characters are pulling off moves they can't do in gameplay [http://tvtropes.org/pmwiki/pmwiki.php/Main/CutscenePowerToTheMax] when the main focus of gameplay is over the top action (like what was done in DMC4, where you were shown action that made your gameplay look weak, rather than say God of War where you were then allowed to do something just as brutal as cutscene Kratos just did via QTEs).
Cutscenes also make certain that the story is being told, whereas it's harder to make certain the point is being gotten across by conversations with an NPC. I don't mean forcing the player to sit down and listen to exposition (that's a bad cutscene), but rather giving the information in an interesting way that lets them know its importance. Often it also makes the player less antsy (how many people have walked their character around while waiting for the NPC to shut up so you can continue?) and more likely to take to heart what is being presented.
This is not the only way to tell a story, but it's also important to realize that it is not a method that should be discard simple due to alternatives.
Hell, voiced over text can be a great way to introduce a game if you do it right (through a variety of ways, including using the background, having it be short and poetic, clearly setting a mood, goal, or obstacle, etc.), despite the fact that it's often frowned upon, and still images are great for games that don't involve a lot of movement (such as adventure games).