Artifacts in Heroes III.

Books and elemental spheres, Angel Wings. Armageddon's Blade is such an overpowered item that it's almost annoying. Although, there are campaigns (The Restoration of Erathia) where it's balanced. I also love artifacts that increase speed and the Legion statue. A small sun-shaped trinket is very useful; I don't remember its name, but it gives +3 to morale and luck. In general, there are many great artifacts in the third game, it's hard to choose. And at the beginning of the game, I'm happy with any artifact, although I usually choose resources or monsters as a bonus.