I've had the reseller hosting account with JustHost for a couple months, and keep finding 'unlimited' reseller hosting for $5/month, etc. I'm wondering if these are legit hosting accounts or what. I don't want to be stuck having 100 sites of a bad host. Please advise.
No, these are not legit hosting providers. There is no such thing as a unlimited hosting provider, the biggest reason for that is because there is no such thing as a unlimited hard drive or unlimited bandwidth. Everything costs money, and companys depends on the clients money to pay for their own cost. A unlimited provider will at the end go bankrupt and he will be refered to as a fly-by-night host No doubts.
FYI,as long as your website is within their TOS,you will be safe. JH will not suspend you for nothing.