I live in the US but I am subscribing to UK's Mac Format. It's simply the best Mac mag out there. MacWorld is extremely poorly put together and lacks content. I have subscribed to MacWorld for many years and when I discovered MacFormat, there just was no going back.
On the other hand, MacFormat has a much higher content value. They have detailed step-by-step tutorials, in-depth reviews with significant numbers of screen shots, etc. It comes with 2 CDs full of demos, shareware, and usually a free copy of one software package (sometimes an older copy, sometimes a "light" version of a more popular software).
They also have systematic reviews of shareware programs, which is a nice touch.
If you use a school analogy to compare levels, I would say that MacWorld is at the K-12 level, whereas MacFormat is at the college level.
If you want more specialization after that you have to subscribe to other magazines, and there is unfortunately not much out there: I find Design Graphics magazine but that's not a US magazine and it's targeted at graphics designers. MacTech is good for mac programming (and the only mag on that topic) but again you have to ask yourself whether a printed mag is a good format to discuss programming....
I would love to see a magazine that goes to the "Professional level". The content would be about how to make you and your Mac more productive, network administration, specs, new computer technologies that (could) affect the mac, performance tests (in depth, not the superficial MacWorld crap), really technical stuff, that would be of value to the Pro users. Maybe a new thread could be started about that.
In any case, I would strongly recommend MacFormat as a general Mac magazine to subscribe to.
PS: Isn't it weird that there is just not one serious Mac magazine in the US and that you have to go to the UK or Australia to find something worth the paper it's printed on?!