As for LA Noire, sure it takes less skill to "beat the game" than say AC 2 or AC:B and less skill (if you're following a guide) to get a 5 star ranking on each case but that still requires pretty much 2 play throughs for most people (who probably don't get 5 star rackings on each case the first way through without guides) as well as all of the misc. collecting, etc. etc.
I would think LA Noire (have to beat 2 times and some tedious searching) would be on par or a little below AC 2/AC:B/Infamous/Uncharteds (each of which you have to beat at most twice, sometimes just once and have some tedious finding). Sure, one could argue that beating LA Noire is easier than beating Uncharted or AC 2 because you literally can't fail but it's not as if those other games are difficult either.
My vote would be *** or ** difficulty.
