Dead Space is not overrated, at least not to me.
The graphics still amaze me. The lighting is some of the best I've ever seen.
The controls, and gameplay in general, is virtually perfect. There are a few hiccups and moments that could have had more polish, but these are hardly noticeable in the grand scheme of the game.
The character dialogues and voice acting is very solid. The actors seem to get into their roles; I particularly loved Kendra and Hammond. Not a whole lot of the dialogue bugged me or made me cringe which is rare in games.
Some of the music is kind of generic, but I appreciated the dialed-back tone of the soundtrack overall, it's a good companion to the atmosphere without trying to hold its hand.
For the most part the art direction is very good. The creatures look cool, the weapon designs are neat, Isaac's various suits are nicely designed and makes for a great looking videogame lead.
The level design is great. You sometimes go back to previous areas, but you never get the sense that you're doing pointless backtracking for the sake of extending the length of the game-- which is also a satisfying 7-9 hours long.
Replay value is up there, mainly because of the new game+ features in which you can just start a new game and keep all your stuff, and the weapon upgrading/suit upgrading system is another good reason for a replay or two.
Finally, while I don't find the game scary at all, the atmosphere and general vibe that the game gives off is fantastic. Games like this are truly rare; it takes a lot of inspiration from sci-fi horror films that are more or less extinct these days and has amazing game design to boot.
I did think differently once upon a time. When the game first came out I went on record of kind of bashing it, saying it isn't scary and that the gameplay is highly repetitive. So I'm not going to tell anyone that they're wrong about the game. However, upon replaying it just a few days ago to prepare for the sequel and after being away from the initial hype and so on, I really grew to appreciate pretty much every single thing about it.
Again, I still don't think it's scary and I would have liked more creative horror efforts than just pop-out scares, but other than that the game gives me the same feel that I got the first time I played through the original Resident Evil-- it's a new environment, a new story, you're not quite sure what's going on at first, who's double crossing you, etc.
I used to scoff at people that said that Capcom should take notes from Dead Space when designing all future Resident Evil titles. Now I scoff at myself for that.
Generally, the more popular a game is, the harder it'll be to get the honor, I'd say, since os many will be fighting for it.
That would be great.