I am by far not a power player. I could care less about builds and high numbers, so my opinion will be worthless to a lot of people.
I started a Necro when I first picked up the game back in November. This has been one of the most enjoyable classes I have played in any MMO. I got my Necro to 20, decided that I wanted to make sure what class I really wanted to play to 80 and tried other classes. I tried Ele’s, Ranger’s, Mesmer… Nothing was as fun, or I guess intuitive, as the Necro, and I kept going back to it. My Necro is 72 at the moment and still fun to play.
As a parrot of other people here, if you are having fun with the Necro, to me that is all that really matters in a game. Don’t let others tell you that any class is crap and that you should be playing another one. GW2 is all about all classes being viable, and from what I have seen it is pretty accurate.