Nabari No Ou = Naruto without the horrible voice acting and a in my opinion way better. Though I only speak on behalf of the JP audio, don't know what the English version sounds like.
Full Metal Panic = Mechs and actually semi realistic battles that revolve around tactics. I say realistic as in its not just a Mech Pew Pew in space battle followed by an instant I win. Though dose have a few sci-fi elements *cough cough* Lamb'da Driver (no clue how you spell it but sure that works)
Full Metal Panic The Second Raid = Not seen it but, it looked just as good as the first FMP.
Air Gear = Dragon Ball with roller blades. What can I say Agito is awesome ... which is why I cosplay him, but anyhow it's basically Gang Wars + Dragon Ball + Roller Blades... a little weak on the story but still worth watch a few times.
Desert Punk = Post apocalyptic comedy, this anime starts off as a comedy, but at the last second turns pretty serious in the good kinda way. Though has it's fair share of perverted antics in almost every episode...
Yu Yu Hakusho = Okay I told myself to try and pick animes that weren't overly common and try and pick ones better then your every day beat em up Shonen anime, but this is an anime that I grew up with and even after recently buying the DVD's can proudly say has stood the test of time. So long story short, this anime is a little long but doesn't feel dragged out like some animes (cough cough Naruto, DBZ) but revolves around dark themed demon hunting and your run of the mill shonen antics.
Toshokan Sensou = Also know as Library Wars, to be honest I don't know if this has a 'murican version. However very good anime as it revolves around libraries which have become self-governed military bodies duke it out against the Japanese government forces in the fight against censorship. Sounds corny but is very good imo.
To Be Continued = I would post some more animes that I think are worth watch in the action category but I is out of time for now