Sony 2016 was the best, 2015 was pretty good too. Everything else is kind of a blur. MS' shows pretty much mostly sucked, I have no real recollection of most of Nintendo's shows either. Sony 2013 was shame in terms of games, I was never blown away much by the whole "we'll let you trade in your games" thing so I'd rank that among the worst, 2014 was only saved by Bloodborne. 2017 was not particularly noteworthy, but the games shown during that show have so far been pretty dang good, so there's that at least.I've been updating the op with all the shows and what games they had, so you can quickly refresh your memory.
I don't care about prices/hardware/policies either in terms of judging E3 shows. Sony 2013 was great because it had awesome games.