GEICO since the 70s (for bikes). Occasionally, I'll shop around, but never find cheaper. I've never had a claim though.
I only had one hiccup with them. When I decided to sell my Gold Wing, I called to ask if the bike would be covered if I let licensed riders test ride the bike. They said no, I said okay. A week later, I got a cancellation notice in the mail. Their reason was that I was allowing others to ride the bike. I wasn't. Point? Be careful how you ask questions.
I'm in the same boat as you regarding auto insurance though (not GEICO). About 18 months ago, the parking brake on my Isuzu Trooper failed and it rolled back into the door of my wife's van - in my driveway. A little over $3K in damage. No other main line company will touch me now.
