I probably won't use any of them, but...

...you might as well bask in the pretty:

          

Also, this is the Encarta definition of badass:

noun (plural bad·ass·es)

Definitions:

a highly offensive term for somebody who is regarded as bad-tempered or aggressive ( taboo insult )


adjective

Definitions:

1. a highly offensive term meaning bad-tempered or aggressive ( taboo )

2. a highly offensive term meaning tough, intimidating, or powerful ( slang )

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My definition lacks the "highly offensive" bit. I always considered it a complement of sorts, unless it's being said derisively/mockingly. Definitely more along the lines of "tough , intimidating, or powerful" than "bad-tempered or agressive". I guess they have to put the taboo stuff in there because it contains the word "ass". Gasp! The Horror!