(as far as I'm aware, this wiki doesn't tend to say that something is 'the best' - after all, there is always a situation where something else will be better. Sprites, Pikemen, Master Gremlins and Skeletons can all be situationally better than Centaurs.)
The Rampart town is a good alignmenttown type with Ranger and Druidhero classes. Ramparts are built by creatures in allied defense of the unspoiled wilderness regions of Enroth. With two slow creature types, Dwarves and Dendroids, rampart armies may be best suited to defensive tactics. Most of these creatures, however, have enemy hampering abilities that can be used to turn the tide against many opponents—especially those dependent on magical attacks. Rampart represents AvLee.
Silver Pegasi are among the fastest creatures in the game, which often offers chance to act first in the combat. However, they are quite fragile and should be used with caution.
Gold Dragons' spell immunity is a double edged sword, their skills cannot be enhanced but nor can they be diminished. Useful in tactical manuver called Dragogeddon.
Dwarves and Dendroids are tough and useful in shielding Elves (or other shooters).
The Grand Elf is a nice shooter, but often blinded (or damaged through spells) by the AI. Thus, protecting this ranged attacker with Double attack by anti magic spells like Anti-Magic (4th or 5th level spells only, up to spell immunity) or Magic Mirror (20% to 40% chance of reflecting spells back to the enemy and then target a random stack) can be useful.