Reno.
Honestly Reno makes a lot of Control decks pretty viable if you build for him. You can slot lots of tech cards and semi-viable cards into them and Reno makes up for anything lacking. The Warlock variants of Reno seem strongest, but most of the classes that can string together a Control deck can make something work.
Tunnel Trogg seems pretty viable if you want an aggro deck to ladder with. I just started playing it this morning, but it's pretty fast and seems like it'll take me up the ladder for a ways until I get bored of it. Doomhammer's are the hardest thing to come by in the deck. There's also always Midrange Hunter or Tempo Mage, and those new flavours of Force/Savage Druid.
Secret Paladin is probably still pretty decent. Raptor Rogue is solid right now too and doesn't need too much dust (though it needs lots of wings unlocked).
Those are all the decks I can think of that don't require anything particularly difficult to acquire to build. Only 1 or 2 Legendaries and not too many Epics anyways.
Honestly though if you're having trouble getting past 18 you should probably just pick a deck you have the cards for and practice with it a bit. Often it's more about learning the matchups and grinding a little bit while you figure out a deck before you start climbing. I don't play that seriously or that much and usually hit rank 15-13 just dicking around when I have time. I've hit rank 3 (I think?) in the past and though the ladder is getting gradually tougher over time I don't think it'd be that hard to hit rank 10 with enough practice on any deck.