I am thinking about buying pet insurance, any ideas?

When my cats were younger, I had pet insurance. After a year or two of never using it, I figured I could have spent that money better. I have two that I want to insure. My cats are getting older, 10 and 11, so I think it might be a good idea. I never want to be in a situation where they need some kind of emergency surgery or something and I don't have the money. I did have a situation where my cat, Gaby, needed some emergency care and it cost over $500. Thankfully, I had the help of my grandparents to pay for it. I don't anymore. (Gaby was a victim of animal cruelty and needed lifesaving care-for Gaby's story, click here)

I am a student and I am perpetually broke. I would rather pay $20 or $30 a month if it helps me pay for a surgery later.

Does anyone have ideas on Pet Insurance companies? Do you have pet insurance? Are you satisfied?