I always have at least two (one for my room that is private) and they have to have beautiful pictures of flowers or birds, cats, etc and the big squares for each day for writing appointments and all my business in. I keep them then and can go back and find the date anything and everything happened the year before. Sort of like a diary!
Even with calendars that can be viewed in a number of different ways on gadgets, I have "a thing" about having a "real" calendar in one corner of the kitchen. (I also have "a thing" about having a few "face" clocks too, in spite of having all kinds of digital clocks "everywhere".) Anyway, I most often look for beautiful, colorful, Nature-pictures (flowers are easiest to find, but the right scenery is good too). I did have to live through one year of cute Teddie bears dressed in month-appropriate outfits; but they were cute and cheerful, and I'd waited to long to buy a new calendar that year. I don't - at all - rely on, or frequently refer to, the wall calendar, though. I "live by" the electronic ones. I just think there should be at least one wall calendar in a home.
To me, desk calendars are a waste of desk space and paper. I'm a minimalist when it comes to my desks.
I always have a wall calender next to my computer. It seems to make it easier for me to refer to dates for bills, appointments, etc. I usually get either one with nature scenes and Bible verses or one with wild animals (wolves and tigers being my favorite).
We have a tradition of keeping a wall calender that features, Australian Cattle Dogs. Our breed of course, and one that has been in mine and my families since I can remember. The dogs are also known as, Blue Heelers, or Queensland Heelers.
We have wall calendars. Paris Glitz to be exact. Ever since we went to Paris we have bought calendars that include photos of this beautiful city. The Paris Glitz calendar photos are black & white in the background with the focal point of the photo in vibrant color.