If we include deer, then I have used slug shotguns (mostly Ithaca 37, H&R Ultra Slug and Savage 210) and muzzleloaders (Lyman Deerstalker .54 and Parker Hale .58) for the majority, but that was by necessity rather than choice...hunted mostly in Ontario shotgun zones until very recently.
For other big game, .300WinMag (Sako AV and Ruger 77), .375H&H (Sako AV, Ruger RSM and Blaser R93) and of course .45-70 (lots of different ones)...just 'cause I like 'em.