mainly depends what makes you hardest in the pants mate. Owning the fastest, or the most economical, or the most available or maybe like the idea of something no one has. I don't think you can make a bad decision, they all do roughly the same thing. As usual above you got one reply saying you dont want the calibre you want
I will say at the top ends of the scale stuff like the 30-378 (an elephant gun necked down to 30cal, 130 grains water capacity) is pretty specialised with a range of provisos to own one. Recoil will be a slightly different level and the amount of powder it burns will start eating throats after a few hundred rounds, you will want to figure in replacement barrels if you are shooting big quantities. The 300 rum is a little bit of a barrel cooker as well with 110 grains water capacity. 300 win for the record has about 89. Brass and components will always be available for most these 30's, coming from a 400cal+ rifle background, most things 30 cal are not hard to find.
My choice just for macho factor, if this is to be your one off 'Cool as f***' gun would be to go a bit bigger than 300win. Give yourself a serious margin over 30-06 etc.