Disagree - someone has to deal with emergencies and investigate crimes, and I'd rather it was someone trained to do so.
But I would like to see them split up into different agencies with different responsibilities, so it's not armed meatheads dealing with every social disturbance
There are some peculiar branches of libertarian thinkers (Stephen Molyneux being a prime example) that think nothing should be government/tax funded, up to and including e.g. roads. He reasons private companies should build them, and make them all toll roads, or find some other way to recoup the costs.