For reloader:
First choice, either 6.5x55 , 7x57, or 7x64
Second : the grand daddy of most modern cartridges the 8x57 (8mm mauser )
Third choice: 9.3x74r or 9.3x62
To hard to choose, so that's why I have most of them.
Factory ammo
1. 270 win
2. 338 win mag
3. 375 H&H