She's seriously crazy hot, and I must admit... I hate most of the similar music, and most of the songs sound the same, but Tik Tok has something about it (plus video showcases her hotness, plus her style)...
Take It Off needs to be her next video. Seems to be the only song that has a good party feel and just seems good.
And while trying to find an acoustic version of her singing (hoping she is like Lady Gaga, who is so post-processed, yet has an awesome voice without the vocal processing), I wasn't able to find one of her singing, but I did find this.
Like most self-recorded things on youtube, I almost immediately hit close once I clicked on it... but considering it's a webcam, it's actually impressive.
http://www.youtube.com/watch?v=CN1lTVn8ubY
edit: and hell, even if Kesha can't sing without effects (truly unknown), the sound of her voice with effects (combined with knowing what she looks like) is still aurally pleasing for some reason.
Don't make me explain it, I have no clue why I think that considering I hate vocal processing, but it works with her.