I don't get the huge praise Dead Space gets, sorry.
Yes, it's a neat combination of Aliens and Event Horizon... sadly, the game never fulfills on either promise for me. The Marker thingie stays too vague, the end of DS1 was a huge mess that made me regret finishing the game because it just felt a whole lot better two hours before the end than after it.
I've started playing DS2, after roughly 3 or 4 hours I was simply tired of the overuse of jump scares. Yes, their jump scares are good, but when that's all you have to offer, it gets boring quickly, IMO.
My biggest gripes with the series, however, are these two:
a) Yes, it's nice they don't need a HUD, but having the health of the wearer displayed in a place the wearer will never see is just... completely impractical, bordering on retarded, and clearly shows that Visceral had no real answer to the question where to display the most important information the player needs to be able to see at all times. I appreciate their design overall, but this is a pretty big flaw in it.
b) When I was playing Dead Space 1, a friend of mine came over and watched for a while. You know what his first strong reaction was? Laughing his ass off about Isaac coming into a room full of corpses and going apeshit while stomping those dead bodies to pieces, hoping to find some loot. Seriously, they couldn't think of a better solution for looting that's less ridiculous? Things like this always take me out of the experience.
Overall, Dead Space is a fun third person shooter series. It's campy, loud and in your face all the time, it looks and sounds great and the "strategic dismemberment" feature is fun. For me, that's about it, though. Best new IP this gen? Nah...