While the Halon extinguisher are still sold and serviced, their replacement the Halotron 1 is equally as good at putting out fires and ease of cleanup. I keep a small Halotron in my vehicles when traveling, a 2.5# in my car trailer and two 5#in my garage.
I would avoid the dry chemical ones myself, they are highly corrosive and a pain in the neck to clean up afterward. The trade off is they are cheap compared to the Halotron, I consider extinguishers added insurance.