Power Girl, which I first saw in the Justice League comics, also appeared in a number of other places. I remember seeing her making an appearance on one of the episodes of Justice League Unlimited (season 1 I think), but the funny thing is, it wasn’t quite Power Girl. It was a Super Girl clone, that was genetically aged into adult age and had a white costume similar to Power Girl. She was an evil clone by the way, and the two of them somehow had a mental bond. She ended up being defeated by the Justice League and appeared in one more episode later on.
Power Girl is the Super Girl of Earth Two, she’s also a survivor of first Crisis and has basically all the strengths and weaknesses of any other Kryptnonian. She has gone through a number of problematic events and ended up staying in the Justice League where she holds a reasonably important position. Anyway, just go check the update at Wiz Kids talking about this Brave and Bold Power Girl preview: http://wizkidsgames.com/blog/2010/03/12/869/.