Mutant League

Bones Justice and company. I still believe this show was pretty good - but it didn't last long at all. This was about mutants pitted against each other in a do or die sports arena. Did I mention EXCELLENT SHOW? Mutant League Football for Sega was also a wonderful time-suck.
Swat Kats

The Radical Squadron. Two cat mechanics are secretly pro pilots of a super-awesome fighter jet and go into kombat to fight an evil cat lord. Great premise anyone? This cartoon ate Duck Tales and deficated Dark Wing Duck.
Samurai Pizza Cats

Another Cat themed fighting show. This show was garbage but it was animated and the main cat had a sword. Auto-watch.
Biker Mice From Mars

Three roided out mice that ride space travelling Harley's come from Mars to battle evil on Earth. I do recall for some reason someone decided to make a PS2 game based on it years later - a disappointment to say the least.
Street Sharks

4 guys get captured and injected with shark genes by a mad scientist and turn into muscle headed, crime fighting sharks. "GENETIC MELTDOWN!!!"
There were a few other shows such as the Tick and Freakazoid that came to mind - but they did last a little longer than the shows previously mentioned and belong in a different category (they were decent). However, there was a "real people" show that not many recall and I made sure to watch it every week as a youth.
WMAC Masters.
The video says it all.
Live action martial arts with dialogue and a storyline. The WWF of martial arts. Someone told me the hostess is a relative of Bruce Lee. Not too sure about that, but when the ninjas come out and the fighters get a life bar like in video games I went bat-shit crazy for the show.
Waking up at the crack of dawn on Saturday to watch cartoons seems like such a foreign idea now... sad. Toodles :(