Many great points made already that I agree with, like all of Pseron's bullets. About the battle music, my complaint is that it has become a warning. You'll be running along, doing your thing, and this battle music kicks in and you start looking around for the enemy. No surprises allowed.
I disagree with the "classes" and "restrictions" folks. I enjoy those aspects of RPGs. They help me define the character I am going to run and keeps me "on course." I'm just a weaker roleplayer than others That being said, I have yet to pick any of TES's ready made classes. I always create a class with the skills I want
As for the "on rails" vs. "open world" part, that really depends on the game being made. If it is a "story first" game (like Metal Gear Solid, SW:KotOR, Telltale Games, et al), then linearity needs to be the rule. Like a book, the story has "chapters" and if read out of order, can totally screw up a book. If it is a "player character first" kind of game (like the TES series), then choice is the rule.
[edit]
Forgot to mention loading screens. I understand the "need" to section games off into smaller parts (memory usage being a huge part), but (using Skyrim as an example) when a Dragon attacks a walled city, then flies outside the walls, it's gone. If you exit (load screen) it will more than likely be gone from the area.