I don't know if anyone has had the time on their hands to go through this thread and list the calibres by frequency of use, but I think it would be interesting. From what I've read thus far, I don't think I'd be far wrong to say that the venerable .303 British and .30-30 are the most frequently named calibres. I've been hunting a lot of years now, and my "go to" rifles are still a heavily modified .303 and my .308. I've shot deer with my 20 ga. and last year I shot a nice little 4 pointer with my SKS.
I know there are a lot of new ###y calibres out there, and I'm not knocking them at all. One of my clients at the place I used to work pooh-poohed me for living in the past but I've got the meat in my freezer and at the end of the day, that's what matters. I tell a lot of new hunters that if you want to get your feet wet for hunting in Ontario, you can't go wrong with .303, .30-30, or .30-06. You can get a good serviceable rifle and ammo for a lot less than let's say a .270 WSM, and if you find hunting isn't for you, you're not out a lot of money. Another upside to the tried and true old calibres is the availability of ammo. I've know guys who either had their ammunition damaged or forgot to pack it when heading out for their hunting trip. Try getting .300 WSM or .257 Roberts or 7-30 Waters at your local gun shop or Canadian Tire in Kenora or some other northern town. By loading my own, I have highly accurate ammo for what I shoot but I also know that if I had a senior's moment and forget my ammo at home, I can pick up what I need locally and sight in quickly. If I was hunting mountains or prairies, I'd see a long range, flat shooter like the new short magnums or even the 6.5 X 55 as an ideal addition to my equipment list, but such is not the case personally. Please bear in mind that I'm not slamming anyone for their choices, but I just thought I'd put in my two cents worth.