Everyone has their favorite games that they have played over the years. Many of these games have sequels. A consistent comment about these games is that it isn't as good as a previous iteration. Now this isn't necessarily a bad thing but it does present what I consider a unfair viewing of new games. Since it is a new release, I'll use the Final Fantasy XIII trilogy as my example.
If you go to your favorite gaming site and look at comments you'll see some a handful of people that love it, some that think its good, others that think its okay, and then those that think it's bad. Take a look at those that think its bad. There is a high chance that those some people will say that it's not as good as FF6, FF9, FF10, FF7, or some other FF that they love. Now I'm not saying that this is the case in all instances but rarely are games viewed on their own merit unless they are a new IP. You can complain about the 25 hour tutorial of FFXIII. You can can complain about the somewhat confusing story of FFXIII-2. When your opinion of a game is based on your opinion of a previous iteration of game, you are looking through rose tinted glasses of the past. The same occurs with other type of media as well such as music and movies.
This happens with a lot of games of the current generation. From Final Fantasy, to Assassin's Creed, to Mass Effect, to Dragon Age, to whatever games have had a consistent presence of the past decade or so of games. Based on my short memory the only series that I can say that doesn't seem to hit this is Zelda. (Disclaimer: I haven't played a Zelda game since Zelda 2 and I'm basing my previous statement on comment sections I've read and participated in)
So my personal challenge to everyone is to give games a fair chance. We all like to be given an honest look without something in our past tainting someone's view.