Beet the Vandel Buster - One of the best Shonen manga I've ever read, especially great if you like rpgs. Only shame is that it's on hiatus after volume 12 and who knows when or even if it will be continued... Still each volume builds up and gets more and more epic as it goes along.
Ranma 1/2 - An amazing mix of action and comedy that will have you laughing out loud since the main character becomes a girl when splashed with cold water due to a curse. It has lots and lots of really good fights.
Overall it's 36 volumes so it's not exactly short but at least it it's not endless and avoids dragging on long past it's prime.