Hearthpwn

This time I didn't preorder the expansion so I didn't get many legendaries, just Thrall, Deathseer, Shadowreaper Anduin from the adventure, a golden Hadronox and a golden Rotface (I may end up disenchanting those last two if they aren't worth it). I don't have much dust either so I want to be very cautious with which DK I craft.

Which ones have been the best ones so far? Which ones do you think have more potential aside from the early days of the expansion?
I know there are many decks with Malfurion the Pestilent and Uther of the Ebon Blade and that it may be hard to tell this early on, but I wanna hear your personal experience with them just to be sure (cuz I don't think I'll be able to pre order the next one either and I don't wanna be left dustless).

Thanks!

wait at least for 2 weeks, be patient and no regret. 

The Druid legendary is optional but versatile, while basically everybody to play Warlock until the next expansion is likely going to use their broken deathknight.

Honestly, while I never planned on crafting it, I got the mage deathknight from the adventure and find it to be hilariously powerful in a dedicated elemental deck. It turns Anomalus into a force of nature.

Patience

Uther and Jaina both seem really solid, but yeah don't craft yet.

That really depends on what you already have. Shadowreaper Anduin is my favorite so far (I have 4) but I wouldn't recommend him if you don't have Kazakus or Raza the Chained. 

Likewise, Uther of the Ebon Blade is good, but if you don't own Tirion Fordring or other strong Paladin legendaries, you won't have much of a place to put him.

If you want to know which one is fun regardless of what else you have, I'd say Valeera the Hollow

I would wait to see which ones are good in decks that you already have the other parts for. I know it sucks to wait, I'm already itching to craft more

I would for sure wait to craft. Most of the heroes call for a more control style deck which will also cost a lot of dust to flesh out to suit it if you don't have the collection. 

If you want an opinion though, I feel almost all of them are playable in some way or another. I haven't used it yet, but from playing against it Uther seems weak,but still a good card. Anduin and Gul'dan and Garrosh can work in the right decks, and work well. Jaina and Malfurion are overall strong. Thrall does its job very well, and is one of the faster heroes. Does seem to leave some shamans hurting without their totems, but that just means it is probably being used wrong. Rexxar is a very good control card, still doesn't show that hunter is a good control class though. I haven't even seen a Valeera yet. Which is why you shouldn't value any of this text.