Hearthpwn

I think Blizz do a pretty decent job in designing and keeping things balanced these days and I think the community does a pretty good job of figuring out how to use cards. Don't think there's any really "hidden" powerful cards that would pop out and change the meta if only given the chance.

If you look at it more nuanced and drop the requirement of them being more powerful than they should be, I think the Dragon and Pirate packages, with cards like Raid Boss Onyxia , basically the mini-set additions from last year, seem underplayed these days.

Also, especially these last couple of expansions there seems to have been a shift where now classes combine multiple packages into a deck. Warlock is running both Imps and Curses, Mage is running both Ping and Big Spell, Control Shaman ran both a Murloc package and a control package, etc. Multiple classes run hybrid packages like that. Doing that has meant that there's more room for players to just run all the good cards, instead of focusing on 1 particular thing and building with less good cards around that.

I think that is also contributing to less cards being left out, even if they are good cards.