This seems pretty obvious to me. Its more of a factual question than an opinionated one, but heck, picks are just more fun!

I definitely remember Akane doing this more than any of the other characters!

This is definitely Akane. I do not even think this is a opinion, its actually a fact. One of the funniest ones had to be in the manga, where instead of trying to get the phoenix pill on a snow mountain, they are at a beach, and Akane's worry for Ranma clouds out her sense of judgement,so she jumps in the ocean in an attempt to come to his aid, completely forgetting that she can't swim until after she hits the water.

I agree with the people above me.

Shampoo might have tried to help Ranma in some situations, which was nice, but Akane is the one who does it the most and is almost always fighting by his side.
I also thought it was funny when she tried to jump in the ocean to save Ranma and forget she couldn't swim, that was pretty funny.
But the point is, even at times Akane might be mad at him, it doesn't mean she will not fight for him when he really needs her. Not only is she there for big event but she's there for the times he was pretending to be another Tendo daughter so they wouldn't end up engaged to Picolet and was stuck in an iron corset. Akane tried to sneak food for him, in anime Ranma refused it, but in the manga Akane basically told him he didn't need to die of starvation, and Ranma was about to eat it until that weirdo Picolet stole the food with his freakish tongue.

Akane, she was always there when Ranma really needed her.

Akane. Akane helps Ranma almost just as much as he saves her.

Akane 100%

With such an obvious answer you wonder why people still question whether Ranma and Akane belong together or not.

Ranma and Akane are always stronger together than they are apart. They belong together.

Akane duh!

Akane, I don't know why anyone would pick Shampoo. Unless he/she were being rebellious or spiteful that is. I guess some one who does not like Akane might pick Shampoo out of resent, but no one can escape the truth, anyone with internet access can find the resources, either the anime or mange, but the manga is a much better choice, to see for themselves which girl risks herself for Ranma the most, and that was obviously Akane.

Akane. Shampoo was not there enough to compete in that competition. Especially not in the manga. The answer is obviously Akane!

Yeah, I'd really have to disagree with anyone who picks Shampoo and There's over a hundred instances that could prove that point so unless asked I won't bother listing why.

Shampoo I'd say brings more trouble then she helps ranma out of.
'
Akane's always there for ranma, she even helps him in some of his schemes like when he was kicked out of the dojo for disrespecting Happosai, Akane goes out at night in the cold to look for with and brings him hot soup, and then helps him in his scheme to defeat Happosai.
She also jumps into a tornado from the Hiryu Shoten Ha blast to get Ranma the paper with the pressure points to restore his strength, even when he looses it and planned to go on a training trip to find another way to restore his strength, and who know how long that would have taken, Akane was going to go with him to help him without knowing when or if they'd ever return. When Ranma first lost his strength Aknae tied him up in that storage closet because she wanted to protect him and she was afraid of someone hurting him while he couldn't defend himself.
I think sometimes part of the reason Akane becomes gets upset when Ranma doesn't fight her in the dojo is because she want to get better and she wants to be strong enough to protect Ranma if he's in trouble and not have to watch helplessly from the sidelines.
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Although Akane denies having feelings for him, She often act on Ranma's behalf . In addition, whenever Ranma needs help or wants something Akane the one who'll be there for him without wondering " What's in it for me?" Unlike Shampoo who always wants to bribe Ranma with dates and even Ukyo, yeah she'll help him out, but in her head she always thinking it'll earn her points with him and give her a better chance at winning his favor. When it comes down to it. Akane's the one who'll be there because she cares and NOT just to get something out of it or just in hope of Ranma liking her more.

shampoo nor ukyo really never did more than try to impress him/ Shampoo has a few scenes where she helps him, ukyo too, but Akane is the one constant that ranma can always count on;

Shan-Pu and Ukyo-chan never really did much to try impress Ranma-kun..as mentioned Shan-Pu had some scenes where she helped but Akane-chan's help is the most consistent of the three.

i agree.

I don't wanna get anyone mad but who choosed Shampoo are so dumb , No one did like Akane did for Ranma

ugh, r u kidding me, the only thing Akane did was hit Ranma constantly for no reason this is a fact. But I'm fine if y'all like Akane.