Oh. I guess we all totally neglected mecha. You seemed to focus more on the ninja/martial arts/fighting and other shonen series like that.
The only recent mecha of any decent quality as far as I'm concerned is Eureka 7. It isn't constant use of it mind you, there's a lot more character development and other plotlines. The mecha in it seems more like a side story, its there, but the focus is not on it all the time.
Definitely worth the watch though, an excellent series.
You could also try the 13 eps series Jinki:Extend from a year or two back but it's fairly mediocre. I enjoyed it, but there are better series out there.