That sort of thing isn't easy to explain, you know. Different things appeal to different people for different reasons, and... well, yeah. I'll just name a couple of titles that are popular with most people.
Blood+
AIR GEAR
NANA
Himawari!
Hachikuro
FMA
... Hachikuro is a little slow-moving though, and boring at times. There isn't much action in it, just the occasional erm, comic relief provided by Morita (whose voice actor is UEDA YUUJI!!! XD).
You can try Texhnolyze and S.cry.ed too... and Appleseed, since you sound like you're into action shows.
Oh, and if you don't mind older titles (older-looking animation and not as good music) and you're looking for something shallow you can laugh at or have a good time watching, go for Slayers. It's hilarious.