Sorry, a little late in replying.
I take Flexeril and also Neurontin (gabapentin), and my doctor has okay'd me taking each as needed (I know not every doctor is okay with that, so please check with your doctor first).
I find the Neurontin really helps the nerve pain, and the Flexeril helps my stiffness. I haven't tried any other meds for fibro, so I can't really compare them to anything else.
I can take a low dose of Neurontin (100 mg) during the day (unless I have to drive somewhere; then I avoid meds totally) and not get overly tired. However, with the Flexeril, it always makes me sleepy.
Sometimes, I break the Flexeril in half, and find it still helps. And it surely helps me sleep better, though I prefer taking something more natural if I have insomnia.
Just as an aside, I requested Neurontin in the lowest dosage possible, because I found it often helps, even at a low dosage. But with the Flexeril, I think 5 mg is the lowest dosage available. The lower dosages can sometimes help, without making you feel you've just been run over by a truck!
Hope you find something that helps!