She still continues to try, 
however.  If I remembered correctly, when Akane was kidnapped by Tarou 
(sp?), Shampoo planed on to kill Akane while everyone else was fighting 
so no one will notice.

Given the way the actual fights between Shampoo & Akane have been shown, 
Shampoo has never seriously tried to kill Akane since AKane is still 
alive.  In the episode featuring Pantyhose Tarou Shampoo saw an 
opportunity to kill Akane while placing the blame squarely on someone 
else.  By amazon standards a cunning and subtle plan that failed due to 
"divine intervention".
This is consistent with Shampoo throughout, she doesn't *OPENLY* 
persecute Akane since this would only alienate Ranma, and she doesn't try 
to kill Akane secretly since she would inevitably end up on the suspect 
list (along with Kodachi and probably Ukyou), only in a situation where 
someone else is already set up to take the blame is Shampoo willing to 
seriously think about killing Akane.

The the final chapter she openly tried to kill Akane, along with Shampoo.
Akane's still alive thanks to Ranma getting in the way of the attack.

On the evidence available in the series, Shampoo's problem isn't that 
Ranma doesn't like her, it's that Ranma likes Akane more.  When Shampoo 
first declares her love for Ranma, Ranma gets a scene thinking about 
whether or not Shampoo would be better than Akane.

Actually, he only compares her to Akane, and thinks that he'd be much
happier if Akane was more cute like that, all the time.

And in everything that follows afterwards it shows clearly that Ranma can 
get along with Shampoo (despite what Kun-chan thinks Shampoo doesn't 
*ALWAYS* glom onto Ranma, just frequently) quite well.  Ranma is usually 
willing to accept Shampoo's gifts of food (outside of fanfic authors 
imaginations, how many times has SHampoo played with drugged food - think 
about it) and often drops by the Nekohanten of his own choosing, usually 
to scrounge a free meal.

And name how many times Shampoo actually cooks food. I have only seen
one frame where she throws a couple of noodles in the air. The other time
she has food, she's serving it. At the moment, the only magic food that
Shampoo used was the stuff that made the person do whatever you say when
the sound associated with the command is given. And Ranma used it back on
her and told her to go home!

Shampoo has a number of good reasons to think that Ranma likes her, the 
problem is he doesn't like her enough.  And when Shampoo gloms onto 
Ranma, Ranma complains about it and asks to be let go, and often says 
afterwards (to Akane!) that he wishes she wouldn't do that.  But he 
doesn't ask or tell Shampoo to stop it.

Ranma just uses Shampoo. Just because he lets her hang around and that
he eats her food doesn't mean that he likes her... And, please show me
where Ranma looks like he is enjoying Shampoo glomping onto him.

Kun-chan...