A lot of users love Nizoral, especially the more experienced ones. I'd recommend giving it a go if you haven't already - it's not that expensive, you only have to use a small amount every few days, and it's been shown in studies (that I've never bothered to read) to be somewhat effective in thickening the hair shaft.
For me, it left my scalp irritated and itchy and my hair would feel dry, thin and generally shee-ite, even when only using it once a week.
I use Moogoo these days and luuuuurve it. It gives me soft, shiny, sparkly hair with wings and fairy dust and magic powers. It'll ninja kick your grandparents.
It won't regrow your kidneys though.
Try Nizoral with a good conditioner to follow it. If it leaves your hair feeling poo then come back and ask more questions.
You should be rotating it with a more gentle shampoo either way. The cleaning agents in Nizoral are pretty brutal.