I would like to have a characteristics or trait or ability or profeciency or something that is 'useful' in day-to-day activities, but is so unique that few people would have it.

For example:
I could choose to specialize in Thundara -- Stun Aspect -- Short Range -- Beastmen.

Few would choose a skill tree specialization like that thus allowing me to be unique.
There would be few skills that we would be able to specialize in, further limiting where we would be unique.
No specialization would be overwhelminly better than any other, so makes it a 'nice to have' but no means 'needed', thus avoiding forced-specialization.