I picked up Uncharted 4 on the Playstation store a few weeks back marked down for $19.99, and was amazed at how much I enjoyed it. I have always been pretty lukewarm on the series--I have the collection which came with my PS4 and have never really been grabbed by the gameplay, particularly the combat. Uncharted 1 feels borderline unplayable to me these days, because the combat is just never-ending, and the story is weak compared to the later entries. 2 and 3 fair better, but are still overly combat heavy, in my opinion.
But wow, Uncharted 4, for someone who really disliked all the gunplay of the previous series, just felt like such a refreshing change of pace. Viable stealth makes such a huge difference. It's the only game in the series that made me immediately want to replay it on a harder difficulty, rather than making me want to turn the difficulty down to the easiest possible setting halfway through just to get through the tedious combat.
I also really liked that they got rid of the supernatural elements in Uncharted 4; the story felt a lot more grounded and believable (aside from some really implausible architecture and 17th century machinery.) I found myself really sucked into it, and ended up spending some time reading up on the real life Henry Avery (and his legend) after the fact. Can't remember the last time a video game compelled me to actually do some (light) historical research.
It's real gem, and a fantastic pickup for 20 bucks.