As far as Ms. Takahashi's manga, all I've read so far are the first two volumes of "Ranma."
It's cute and funny, and all that, but it doesn't look like something that will hold my attention over the course of several dozen volumes.
"Urusei Yatsura", her first big hit, is a standout old school anime title. You could think of it as "The Simpsons" of Japan.
Unfortunately, "Urusei Yatsura", in manga form, isn't available in English. Viz had a version out that condensed the series into left-to-right reading volumes with Americanized translations. These are now out of print.
I was able to pick up the first volume translated into French. I can't exactly read French, but I can get the gist of things. I picked up the second volume in Japanese, which I can't read at all. I've seen the animated versions of these same stories so I can follow them. However, for the stories I haven't seen, Takahashi's artwork and visual storytelling are very clear and well defined. She's able to express so much of her plot and action through the artwork itself. She's definitely a great talent.
According to something I read once, Rumiko Takahashi is one of the top taxpayers in Japan in the entertainers category.