You can save nearly $20 on Sanctum ($40.44) right now at Walmart. One of the most fun co-op board games I’ve played, Sanctum is equal parts hack/slash/loot and role playing adventure-in-a-box.
What I like most about Sanctum (apart from the amazing illustrations) is that as your squad of heroes progresses, your gear gets better. This adds a mechanic that most race-the-deck / race-the-clock / beat-the-dice co-op games don’t have. It even has a final boss, the Demon Lord, for your party to reach and (hopefully) slay.