Ultimately, moving coil, but it depends on how much you have to spend. If your limit is $150, a moving magnet is all you’ve got baby!
That isn’t to say there aren’t some great moving magnet cartridges, especially vintage models. Rather, the best solution – technically – is the moving coil design, because of its reduced moving mass and therefore greater linearity and micro-dynamic accuracy.
Lower mass means lower inertia and therefore better transient response and high-frequency performance. All of that translates to better dynamics, detail, lower distortion and more of that elusive ‘air’. I’ve written quite a bit about this here.
Marketing departments everywhere have tried to convince people that lower-cost moving magnets are “as good” or “nearly as good” as moving coils, but the fact that they even need to try to convince people of this tells you something. They still have these inherent design limitations and speaking from experience, they simply aren’t as good.
Because coils are technically better, manufacturers also tend to spend more on these designs, using better diamonds, more expensive boron or even diamond cantilevers and better coil wire. This means you can spend a ton on a good MC cartridge, but remember that a really good moving magnet cartridge will be better than a cheap moving coil. You get what you pay for.
The caveat here is that because moving coil designs generally have much lower outputs, you need higher quality electronics and even a step-up transformer to get the most from them. People who audition really good MC carts in systems limited by a basic phono preamp might say something like “it didn’t sound that good” or similar.
Don’t expect a really good moving coil cartridge to sound its best on a built-in or cheap external phono preamp. You’ll need a step-up transformer to get the most from a moving coil cartridge.