Not sure about everyone else, but I only do it to see the true ending without giving up and resorting to youtube. What do you mean by "7th to get the Knightfall ending"?
Completing 7 most wanted missions is the minimum requirement to start the Knightfall Protocol. You need all 14 for the epilogue.
And i'm seriously baffled at all the Riddler trophy hate in the thread, AC and AK Riddler trophies is collectibles done right. First of all, their locations can be revealed easily via gameplay, so it's not an Assassin's Creed feathers or GTA IV pigeons situation, where you have to hump every last bit of geometry to find them, and second, many of them require you to think about the solution, use your navigational skills to get to them, or sometimes both, which feels much more rewarding than just having them lie around. Granted, they could do with removing some of the redundant ones in AC and AK, but the more inventive ones make up for those easily. How were they more fun in AA? The actual trophies didn't require any skill or thinking at all, it was just a question of having the corresponding gadget unlocked to tear down a wall or cross a gap to get to them. As for the Riddler races, i admit at first a couple of them pissed me off as well because i was trying to rush through them, but it has been said so many times, they are so incredibly easy in first person mode that it's a total non issue.
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