4 was great, but the story was a little up and down. I felt quite often that they were covering all angles to make sure that Drake's story was explained and wrapped up as neat and tidy as possible, instead of just focusing on making it a crazy adventure. Knowing this was said to be the end of that part of the franchise, I could look passed that flaw fairly easily since the rest of the game was tight.
LL was almost like Nadine and Chloe weren't really all that into the adventure itself, and weren't all that blown away by the loot either. It was more about the reasons surrounding it. Where as with Nate, it almost always felt like he was there for the adventure, and the loot as great as it was, was secondary to it.
I would rate 4 slightly above 2, with both being superior to LL, 3, and 1. There really isn't one game in the series I would say that's bad, just not as good as 4 and 2, that's all.