It all depends what you want to do with your rifle....
The 270 is really versatile and a flat shooter but still burns alot of powder and delivers a good amount of recoil.
I have a 6.5x55 in stainless and it shoots like a charm. Clover leaf groups now and then, depending on circumstances. If you want a good allrounder, the Swede is a good choice - as said, a wide range of bullet weights are available, but you'll have to reload to get what you want. Most factory offerings are 140's and you might have to mail order. No Walmart ammo there.
The 243 is a great caliber but it can be a little anemic if you want to move up and pursue bigger game in the future, or if shots aren't well placed. Also, some say the 243 has the tendency to burn up barrels quicker, if you do alot of shooting.
I would suggest the 7mm08, the 6.5x55, or the 270. 7mm08 is ballistically superior to the 308 which IMO has the trajectory of a banana...

If you're thinking of getting a 308, you might be better off with a 30.06.
Regards