Just 4 but I got a late start and haven’t been power-leveling.
I only wanted 1, but then I wanted a red Draenei too cus they’re red, so made another Pally but went Ret for the 1st time since Wrath and just got to 80 and I’m plowing through Delves now working on my trinket collection (/sigh) while also trying to gear up. 
Wanted to try Delves as Demo, so my Lock got dragged through Delves too, had so much fun, I just kept going, another 80.
Needed to play my Priest, was my main before Paladina kicked them to the bench and I sometimes miss playing the class. So I spec’d Shadow for Delves, again I had so much fun and kept going to 80.
That’s 4 and I am DONE!
Well maybe BM Hunter, Frost Mage, one of my DK’s and possibly a Shaman and this lamp.
But that’s all I want.
…
Just 1 80. Not a lot of time to play + TWW wasn’t really interesting enough to get me excited to do it a bunch of times.
Might do one more but the choice of which is tough.