well, claymore is amazing. i've read all the manga that have been released so far and have watched a bit of the anime, though i'm waiting for a box set release to actually buy them... but yeah, great plot and lots of fighting, and amazing art style/animation ^.^
avenger is also really good, and seemingly lesser known, if you don't mind some space stuff, but it's not really too focused on that.
technolyze is really amazing- great animation, great plot, just all around fantastic
outlaw star is one of my favorites, but it's got guns and a bit of mecha, well, more like grappling space ships... lol. but a great story
blue submarine no. 6 is another fave. it's like a mini series, but beautiful animation combined with cg, awesome plot, etc
i'm sure you've seen fullmetal alchemist, but i have to mention it because i love it so much ^.^
witch hunter robin- another with an intriguing plot and beautiful animation
magic knight rayearth is fun if you don't mind older anime that is slightly corny at times, lol. the "ova", which is just a few long episodes that are completely different than the original anime, is really good as well, a lot darker and more serious
wolf's rain is another i'm sure you've seen, but another of my faves. it's just all around amazing.
another fun one is azumanga daioh, though i'm sure you've seen it too
.hack/sign and .hack legend of the twilight. probably have seen it, but great nonetheless, hehe. i really want to see .hack roots, but again, waiting for a box set, lol
ninja nonsense is hilarious! my fiance and i are cosplaying from it this year ^.^
there are others, i'm sure you've seen them though, so i will just leave it at that, unless i can think of some more... lol