Hearthpwn

When GvG came out, I really wanted to try Bolvar Fordragon, so I spent 1600 precious dust on crafting him when I was still missing some good legendaries and a lot of epics

I had fun playing him, but since then I've definitely decided to save my spending dust for epics.
With that dust alone, I could have made multiple dragon decks and a dreadsteed deck, which are decks I've really wanted to play but been unable to due to a dust shortage.

What cards have you regretted crafting most?

Varian Wrynn and Cenarius. 

Varian wrynn I was so hyped about that wallet warrior boost...

Chillmaw such a waste of dust.... 

Varian Wrynn...

>.>

Pre-release hypers should be burning in Hell.

Gruul when I was still new to the game.

I think I win (lose)... Nat Pagle...

Apart from legendaries from packs, these are legendaries I have crafted (not in order): Alexstrasza, Lord Jaraxxus, Malygos, Grommash Hellscream, Tirion Fordring, Archmage Antonidas, Dr. Boom, Justicar Trueheart, Sylvanas Windrunner and the most recent one is Harrison Jones.

If I must pick one, probably have to go with Harrison Jones. He didnt perform well in my Priest and Warrior as I expected. 

bloodmage thalnos as he is the only legendary i crafted that i am only using in a single deck. the other i have crafted are sylvanis, dr boom and alexstrasza XD

Cairne Bloodhoof

I don't regret anything I've crafted, but Gazlowe is probably the closest thing. Also I crafted Prophet Velen and then opened him in my very next pack, so that could count as a different type of regret, though I don't regret having him in my collection.

Toshley

Kept trying to make him work in Rogue and Mage decks, but never could. 

Varian Wrynn hype D: I still have him and hope that one day he will be good...

Quote from Prudence94 >>

Chillmaw such a waste of dust.... 

As for me, I would have to say Baron Geddon.  Yes, a staple in CW, but hardly ever used or seen in any other deck.  And a minion I probably haven't used in months.

Golden Mogor the Ogre. Basically because i thought it could help me deal with swapms decks in heavy spell shaman/mage decks.

i think that is difficult  to be worse no?

Know what did you feel, bro. Craft Mal'Ganis, then 3 days later got him from pack... Wasted 1200 dust...

My biggest mistake was crafting a Leeroy Jenkins just after his nerf(just starting to play, and everyone using him these days, but after neft, almost noone using him... Disenchant him and return at least 400 dust, but still...

Well I haven't crafted any BAD legendaries. The worst was probably Harrison Jones as I don't actually use him in any decks right now. But hey, it's still better than the golden Bolf Ramshield I DE'd to get him.

I don't regret crafting any legendary. I crafted Ragnaros the Firelord, Archmage Antonidas, Alexstrasza, Ysera, Sylvanas Windrunner, The Black Knight and Justicar Trueheart.

I thought of crafting Malygos to try in various Mage decks, but got him from a pack. I'd probably have regretted crafting him. It's a shame there's no good Malygos Mage deck.

I prefer playing Mage, so since the TGT release I've been thinking of crafting Rhonin. He's considered weak, so that might be a mistake. I have the dust, just haven't decided yet.