UPDATE: The information in this article is out of date (published September 2019), for the best information, check out Laterus's FAQ and Guide
Full Article: “Shop Titans: Heroes — Which to Hire, Retire, and Avoid”
Summary[]
Heroes to Hire:
- Thief (1-2)
- Mage
- Monk (level 15)
- Musketeer (level 25)
- Ranger (level 30, only if you have an available hero slot)
- Sorcerer (level 32--only 1!--can retire Mage at this point if need be)
- Wanderer (level 35)
- Samurai (level 45) (hire 2 when possible)
- Spellblade (level 48) (Pretty useless unless you replace a lower level Spellcaster with it)
- Ninja (level 50) (Hire as many as you can when you can!)