The basic technology of ice cream makers — be they high-end commercial machines or low-tech home models — is basically the same. A cold surface is created, usually with the help of some sort of refrigerant (or ice brine). An ice cream mix is exposed to that surface where it freezes, only to be scraped off to allow more unfrozen mix to contact the freezing area.
The hand-cranked churn was of course the go-to contraption for most homeowners when I was a kid. I can scarcely remember a 4th of July where I wasn’t conscripted to put at least a few licks in on the crank (and I didn’t even like ice cream). Those old machines are largely out of vogue these days, in part because they were a pain in the neck (and arm and shoulder), but also because these days they’re actually more expensive than the motor driven “frozen tub” variety. These types of machines cost under $50 and feature a removable bowl — plastic on the outside, metal on the inside, and in between a refrigerant that chills to about zero degrees Fahrenheit. They work pretty well provided your mix is very cold and the freezing process goes off without a hitch. Otherwise, you have to re-chill the tub before you can try again (pointless, since that takes another 12-24 hours, by which time you and your dinner guests are eating cake swimming in a pool of peppermint crème Anglaise). Some people solve this problem by simply buying an extra tub to keep on hand, just in case.
I was one of those folks, at least until I got tired of having to worry about my freezer tubs de-frosting and bought one of the expensive variety with the built-in compressor. They have come down in price quite a bit the last fews years, but will still set you back a cool $250 at the very least. The advantage to these beasts (and they are beasts, weighting in around 30 pounds or more) is that they’ll run all afternoon without any part of them having to be stuffed back in the freezer. Which is handy since you’d be surprised how often a frozen dessert mix doesn’t freeze in the allotted time frame.
Which brings me to an important point: size. It’s still possible to spend close to $1,000 on a compressor-drive ice cream maker, though you really shouldn’t. Why? Because the extra price is usually related to capacity. Instead of a 1 or 1 1/2 quart bowl, these machines sport a 3- or even 4-quart bowl depending on the maker. Bigger bowl size means a bigger compressor is needed to chill the bowl down. The problem however is that despite the bigger compressors the higher-capacity machines usually take longer to freeze a batch of mix than do the smaller ones. And as I mentioned, if smooth, creamy ice cream is what you’re after, speed is everything. Better to go with the smaller, cheaper models — and even then only freeze half batches at a time. It takes longer, but the end product is well worth the wait.