I recently discovered something that I hadn't seen mentioned before.

I like the look and style of the ebony blade but when playing a non evil character it can be frustrating to find ways of getting it to full power without breaking character.

Well it turns out the Dark Brotherhood members all count. So if you are "good" and choose to destroy the Dark Brotherhood just take the Ebony blade with you into their hideout.

You will get at least 3 power ups from killing all the assassins.

The cannibals in Namira's quest count, I think, the problem is of course that a good character would never participate in that... You could however do Lisbet's and Banning's personal favors, and then RP that you found out about their eating habits.

And you can do Ondolemar a favor before going Thalmor-bashing.

If you kill Madanach in Cidhna Mine, Thonar Silver-Blood probably will be tagged as your friend - why don't get your revenge on him? (Getting revenge by killing someone might be to stretch it for a good character though).

Interating. I never wanted to use the Ebony Blade because none of my characters would kill their friends, but suddenly I see the possibilities - maybe I should do something else than just hide the blade away on my next sword-wielding character...

If you do the lighthouse quest in Solitude those two lying Argonians count as well, I think.