My favorite would have to be the .22-250. I had never dealt with one till last year and after my buddy dropped a dog at 325 yds I was hooked on the caliber it was amazing I thought he had missed because it took the bullet so long to get there but that loud solid thump left no doubt as to whether or not he hit it. We started doing research and that is a flat round you can sight it in at 200 and be on at 4 to 250 yds and only drop 5 inches at 300 yds and about 16 inches at 400 yds. Very useful for us flatlanders you can easily nail a dog out to 400 yds with his gun. But the caliber I most commonly use, until I can afford a .22-250 in the AR-15 platform, is the .223 shooting USA 45gr HP's out of a Colt accurized CR6724 flat-top AR-15 with a flat silver nikon scope on it and it looks awesome. Sweet rifle that will shoot a dime sized group if I do my part and has killed some dogs, hogs, and a fox.
That is my long range preferences but for the nitty gritty in your face shots I like a mossberg 835 12 gauge loaded with some 3.5 inch BB's.