Never "build off the previous title." Why, WHY is it so hard for developers to strike this balance?
On the one hand, you have companies like Nintendo determined to never ever improve on what they've done, and instead must work from the ground up whether the new idea is practical or not.
And on the other hand we have games that feel like the same thing every time. Madden, COD; it's more like an update than a sequel, and they come out every year. And don't get me started on all of Nintendo's "revivals" aka ports from 2 gens ago.
One great example of a sequel done right is Super Smash Bros. Call it a party game or whatever, but the original was a great game. A great game, yes, but with much more potential. So in Melee, they took the game and brought it to the next level. They took the original piece, sandpapered away some of its flaws, and built shiny new content on top of the foundation.
Every E3 now, the Big 3 companies seem determined to "change the way we play games." Why? Is something wrong with the way we play games? I'm all for innovation, but innovations relies on a solid ground to work up from. Instead, companies are trying to completely depart from contemporary gaming for the sake of being new.