Hi Thisdesertrose,
Hope I'm not too late in responding. Been away from the topic for a bit now and just now returning. My apologies to my readers. You should start to see new topics and articles coming up soon.
As for your question here, pretty much all Martial Arts should use the opponent's momentum and strength in your favor. If you aren't you're just muscling things. In fact, if you study body mechanics, any and all physical activities work better if you work with your momentum and strengths and not against them.
Amethyst22 did a great job answering. I personally study Tai Chi and have done Tai Chi sparring (though I honestly don't do a lot of combat) and it is a lot of fun. I've also seen Aikido practioners and they are great to watch.
The key is really to pick something that appeals to you. I would go and watch a class or watch a demo to see if what they are doing is interesting. There are a few articles up already from the past in the
Finding a School that might help. Also, my section about
What is? goes through a bit more specifics about various arts and how they differ.
If you have any more specific questions, please feel free to ask.