Reading another thread made me curious about how other players perceive the relative strength/utility of the heroes. So, please feel free to join in on ranking the heroes from most to least useful. Explanations are also most welcome.
Here is my ranking
1. Barbarian
2. Ranger
3. Valkyrie
4. Assassin
5. Dreadknight
6. Horselord
7. Paladin
This ranking is not actually as linear as it seems. I decided to go with frequency of use as a ranking system. Ranks 1-4 are all possible first heroes for me (depending on the situation). The DK, and HL have their roles as well. The only hero I rarely use is the paladin, he just seems a bit lukewarm at everything, and lacks a clear role (although he can be a beast with some items). So, I might consider a paladin as first hero on a map with many level 3s.