I don't use on-camera lights myself so I can't actually recommend one. But the Genaray lights have some good reviews; on a tight budget you could get the Aputure AL-H198 instead. With any video light, check the CRI (colour quality) before you buy - under 90 will give poor skin tones, you need at least 95 CRI if possible.
Thanks. I just ordered the Aputure AL-H198 from an online site. I checked out the Generay lights and strange enough the manufacturer doesn't state the CRI for any of the on-camera models I've seen -- and several reviewers complained about the same. Some have claimed to have tested it and state that one of the better models is no higher than 85.
OK, that's worth avoiding then - I have an 85 CRI light and skin tones look like mud!