Hearthpwn

concede or kill myself. though I usually play to the bitter end even if there is only a 10% chance of winning. I've been surprised on when I can turn it around with certain decks. I just love it when some starcraft idiot spams well played and I beat him. 

depends on the game played, sometimes i let myself get killed, others i concede inmediatly, others in his turn, others i attack the biggest minion

If it is a good game, I'll usually give him 5-10 seconds to kill me, with concede if he starts goofing off.

If I am a little annoyed, I'll concede on my turn.

If I am playing against a warrior who does nothing but sit around and gain armor all game.  I'll quit and reload, so he can sit there playing with himself for a couple more minutes until the game finally tells him his opponent left.  Meanwhile I can load a new match with no risk of facing him again.

If it was a decent fight and he wasn't spamming emotes (and I'm not in a bad mood) generally I'll give them a few seconds to finish me off, only conceding if they start BMing/playing every card.

Otherwise I'll just concede.

I will occasionally finish by attacking into lethal if I'm somewhat bitter and have a weapon equipped, though only if its easy to do so. Rarely will I cast spells on myself.

That said I tend not to concede or end the match unless it's both clear they have lethal and they know they have lethal. You can make surprising comebacks sometimes.

I've played thousands of matches and never conceded once. I always play through. 

Usually, I'll just concede if he has lethal on board and I can't deal with it.

If I have quests to complete, I'll play those cards then concede.

If he has set up a combo that will kill me, I'll usually let that go off. Things like Mimiron's Head into V-07-TR-0N

Turn off the app and do something else, let the game hang.

Commit Sudoku

(or Suzuki, Yamaha, Honda ...)

let me tell you people a story it was in time when loe was published i was in a match aginst someone with 2 8/8 minions i had 8 lifes a Summoning Stone and a Flamestrike i almost concede i played the Flamestrike and the Summoning Stone summoned minion i never seen before it was Prophet Velen the Flamestrike killed both of his minions and he concede and that why you shouldn't concede

Once i know I will certainly lose, I often just concede on their turn as it allows me to move on to the next game more quickly. I never rope.

If it's against a control deck with Golden Monkey and I'm sure to lose (he could kill me in two turns with board, I have 1 card in hand (haunted creeper), and he has 40 armor) I spam "well played" as much as possible and end my turn without doing anything (unless it helps him (play the haunted creeper to boost frothing for example I guess). This communicates that I want to see what legendaries he gets and he hopefully doesn't kill me but plays it out to make an epic turn (like a ghazrilla with 192 attack)

but if I'm about to lose to a secret play turn 7 I just concede.

if I can kill myself I do

There's really no one answer.

Sometimes, I play through it especially against a unique deck, if only to possibly what comes next. Sometimes I play on just to give the opponent the chance at a final blow (so to speak). Sometimes, I simply play on because the opponent was a good sport / made some epic comeback / etc. At other times, I concede / suicide depending on my fancy.

Concede. My best match is always the next match.

4th option: make a comeback and don't lose.

Quote from Mogg_Maniac >>

If it is a good game, I'll usually give him 5-10 seconds to kill me, with concede if he starts goofing off.

If he showed bad manners, I just concede. 

If the game was interesting and/or the player had good manners, I either suicide myself (if I can) or give my opponent 10 seconds to finish me off properly. If he/she starts goofing around, I just concede. 

As a one-time avid tournament chess player, I've learned that most games never end in checkmate.  Once the handwriting is on the wall it is expected and courteous behavior to resign.  And that's generally how I behave in Hearthstone as well.  However, if I think there's a reasonable chance that my opponent might still screw up I'll stick around just in case.