I get really annoyed with insurance companies/brokers who don't bother to give their best quote because they are relying on customer inertia.
What particularly gets me is, if you ring to say 'you're not competitive, they'll usually reduce their price! If they could do that, why didn't they do it in the first place? So I shop around every year. It takes a while and piles of patience but usually pays off. I have bikes and household renewals next week so double dose of patience required.