Hearthpwn

Ok so my plan was to craft Yogg but we obviously know what happened there. I have been playing a lot of Rogue but I already have Van Cleef. Looking for some ideas of great cards to craft - I don't have Rag so that's up there. I do have Sylvannas and out of the core set I have Van Cleef (as mentioned before), King Krush and Jaraxxus. Any ideas would be appreciated!

You have a ton of options. Rag and Sylvanas are both great cards that can find a spot in just about any deck, but if you like playing rogue, Xaril or Thalnos are good choices too, but i don't think i'd give them priority over Rag and Sylv. Deciding on what deck type you want to play could help you decide which legend to craft next, but for now, I'd probably go with one of the first two since they are both just solid cards no matter where you place them. 

Just reread, your post and noticed you said you do have Sylvanas :p well then Rag is a great choice, or almost any of the Classic class legendaries are great too

Xaril isnt a bad idea, I forgot I have Thalnos - hes the man, something you don't realize when you start playing the game.

Leeroy Jenkins is a good finisher for rogue decks.

Xaril is about in the same league as Thalnos as a solid card that gives you value, but probably isn't going to win you the game on his own, but his toxins are all really useful spells

Hmmm Leeroy could be the ticket, plus I could use him in Zoolock as it slowly fades away from being relevant. 

Bloodmaga thanos is used in both rogue and shaman.

Just craft the Yogg. After the nerf comes, you can test him out if he still works. If he doesn't just disenchant him and thats it you get all your dust back and can now craft another legendary. Its not like theres something to lose by doing this.

Rag is an amazing card that I run in five different decks. Thalnos is second legendary to consider. I would craft them in that order.

As a rogue main, I say craft all the rogue legendaries *^*
But in seriousness, depends on what kind of decks you like lol. Flik is one of the best legendaries for rogue if you don’t have her.