The most selfish 1 letter word: I.
Avoid it.
The most satisfying 2 letter word: We.
Use it.
The most poisonous 3 letter word: Ego.
Kill it.
The most used 4 letter word: Love.
Value it.
The most pleasing 5 letter word: Smile.
Keep it.
The fastest spreading 6 letter word: Rumour.
Ignore it.
The hardest working 7 letter word: Success.
Achieve it.
The most enviable 8 letter word: Jealousy.
Distance it.
The most powerful 9 letter word: Knowledge.
Acquire it.
The most essential 10 letter word: Confidence.
Trust it.