Coming out of the subway and getting the first glimpse of the park was a pretty awesome feeling.Fenway Park is a dump and that's being nice about it. Unless you have one of the few good seats in the park, the sight lines are terrible. There are poles everywhere which create a lot of obstructed view seats. The large number of aisles create a constant flow of traffic which further blocks your view. The seats are like cement so bring a cushion. The hot dogs are awful. As billhill mentioned, get a sausage sandwich outside the park. They're hot and fresh and you can get a lot of toppings if you want. There's also a lot of good pubs and restaurants in the area so eat before you get into the park. Fenway Park is an old, dirty, smelly and cramped ballpark.
I grew up in Massachusetts so I've spent some wonderful nights at Fenway Park but it's simply not a good place to watch a game. That being said, if you haven't been I would recommend at least one visit and then you can make your own decision. I will have to say my fondest memory of going there as a young boy was the feeling you get when you get to the top of the stairs at the Kenmore Square subway station and you look up and you can see Fenway Park and you know you're almost there.