I've come to really like Sekirei, now I'm looking for other similar Anime...

Don't get me wrong, the fan service is nice to see.. but Sekirei also has a good story, and good characters.
If the story and character development wasn't there, I wouldn't like it nearly as much.

I've already watched Rosario+Vampire.
Good premise, decent storyline, I just wish the characters were older. (not high-schoolers)

I've already watched Infinite Stratos.
So-so.. some nice parts, but just didn't do anything for me.

I've already watched Freezing.
Good story, Satellizer is a wonderful character. But the other characters need more work.

So... I'm here to ask....

What else should I be looking at?

Any suggestions?

Thanks in adance.