Honzi/Guides/Hearthstone/Adventure Priest
This deck is designed to easily beat many normal and heroic bosses in "Solo Adventures" mode by using a 5-mana 5-card combo that only requires 280 dust.
Playing:
Critical cards:
Embalmbing Ritual 1 Common Priest SoU
Holy Smite 1 Priest Basic
Knife Juggler 2 Rare Neutral Classic
Radiant Elemental 2 Common Priest JtU
Test Subject 1 Rare Priest TBP

Some alternate cards can be used to achieve the combo, but require additional dust. Include them if you have them:
Forbidden Words 0 Rare Priest RoS Alternate for Holy Smite.
Topsy Turvy 0 Common Priest TBP Alternate for Holy Smite.

The other cards in your deck should help you draw the combo and survive against enemy minions and spells:
Acolyte of Pain 3 Common Neutral HoF
Bloodmage Thalnos 2 Legendary Neutral Classic
Coldlight Oracle 3 Rare Neutral HoF
Dead Ringer 2 Common Priest TBP
Loot Hoarder 2 Common Neutral Classic
Northshire Cleric 1 Common Priest HoF
Novice Engineer 2 Neutral Basic
Power Word: Glory 1 Common Priest TGT
Renew 1 Common Priest AoO
Shadow Visions 2 Epic Priest JtU
Shadow Word: Death 2 Priest Basic
Shadow Word: Horror 4 Rare Priest WotOG
Shadow Word: Pain 2 Priest Basic
Shadow Word: Ruin 4 Epic Priest Classic
Stonehill Defender 3 Rare Neutral JtU