For dealing with creatures, Paladins/Zealots are the best. They are tough and relatively strong (especially after the second upgrade), and they only take 50% damage from ranged attacks. In general, one of my favorite heroes for Humans is Laslo. First, Zealots become incredibly powerful under him. Second, he gains readiness very quickly, which makes further creep development easy. He doesn't need any spells; just take the Haste perk, and then use Inspiration to quickly reach level 3. Instead of Haste, you can take Retribution; it depends on your preference. However, against Stronghold, Necropolis, and Magic heroes, the first option is preferable.
Bow down and hear our cry,
Our earthly rulers falter,
Our people drift and die,
The walls of gold entomb us,
The swords of scorn divide,
Take not thy thunder from us,
Take away our pride.
G.K. Chesterton: English Hymnal