In California McGraw gave me the best rates.
It really depends on where you live, your age and driving record and how the insurance company in question rates bikes. Some go straight CC, so a GSXR600 would be cheaper than an SV650 despite the fact it has nearly twice the horsepower. Others rate by model, and will charge you an arm and a leg for a supersport (like the GSXR600) and hardly anything for a sport twin (SV650).
Your best bet is to just call every company that insures in your area and get quotes. It sucks having to make so many calls, but it is generally worth it. Also online quotes are almost always higher than talking to an agent as a rule.