Reading thru everyone's post there are a few of the new guys that creep in every now and then, 28 nosler and 6.5 creedmoor. Two cartridges seem to be at the top of a lot of people's list, the tried and true 300 Win Mag and another not so new but not so old cartridge the 338 RUM/Edge. You could throw the 338 Lapua and its Ackley Improved variant in there too, as well as, the 340 wby, as all three of them are very similar in performance, with the Ackley rising to the top by about 100 fps. The others that seem to be up there on people's list are the 22-250/22-250 AI, 7mm Rem Mag, 270 Winchester, and 257 wby. The 375 H&H/375 Improved seems to be the most popular for the stuff that will kill you, dinos and such. I don't know that you could draw any difinitive conclusions from this but it appears most of us would tend to stick with the tried and true over the newer gucci stuff. If I had to guess it probably has more to do with ammo selection and availability than anything. Being able to get ammo wherever you are in the world at the time is important. The other reason is these calibers just plain getter done!
Good post guys! Keep them coming!