Ranma 1/2, according to me, is a far better creation of Rumiko Takahashi than Inuyasha, though I know all don't feel the same, as it should be.
The thing I like the most is the CONCEPT. I don't remember watching or hearing about any similar Anime where the protagonist has a gender-problem and turns into a girl when splashed with cold water. This is really admirable.
But at the same time most other things like the fight between the fiances of the protagonist, the true but hidden love between the main characters and a tsundere girl failing to convey her feelings, are pretty common. This anime also has many couples and characters which give the viwers the opportunity to ship different characters, like Ryoga X Ukyo or Kuno X Nabiki and other odd ones.
The creator has shown no misery in adding humor to the anime, I must say.
Martial arts should have played a more important role in the series, though it dosen't matter much since there are many other things to love and to enjoy!
There are several cute romantic moments. Ranma X Akane moments are my special favourites, though I feel bad for Ryoga.
There's really nothing special to mention about the opening and closing themes, though they were not the 'memorable' ones, but they were quite matching to the theme of the anime. Here I must say that I really liked the background music!
To sum up, Ranma 1/2 is an anime which you'll enjoy a lot, if you watch it from a simple viewer's point of view. You would get engrossed in the story and also may see yourself as an character ( and there's a lot to chose from!). But you may find some flaws if you watch it as a critic.
Despite the flaws, for me Ranma 1/2 has always been entertaining and it will always remain one of my favourite animes!