I think the 340 Wby would be my pick of a favorite. That choice is likely fueled by Bob Hagel and Ross Seyfried writings. A friend of mine had one in a Mark V and it grouped very well with old Barnes X 225 grain bullets.
I do not own a 340. But have, had a donor rifle and brass for years. Other projects took priority and I learned to appreciate the 338 Winchester.
The 7mm Wby is also very intriguing to me as a 7mm fan.
I have a 300 Wby M70 stainless New Haven Classic. Basically bought it because it was somewhat usual chambering in that rifle. I do think it is a great cartridge.
