Suggestions

"BunnyHop" Custom Enchant

Gives the player permanent leaping.
enchantment level is 2.

Obsidian Breaker

This one could be really really good for Factions servers. Having your pickaxe enchanted with Obsidian Breaker enchantment would make it 25% faster to break an obisidan at the 1st level of the enchantment , 50% at the 2nd level , 75% at the third level and insta breaking obsidian at the 4th level.