Well, I have owned all three, and killed a lot of deer with all of them.
IMHO.... The 280 remington is the very best of the 30-06 based cartridges for deer sized game. Yes, it may be harder to find ammo, but it's not that hard, and if you hand load even better. So many great 7mm bullets out there to choose from. The .280 Rem covers all the bases in a deer cartridge.
That said..... It really should come down to what rifle you want to buy, and is it available in the cartridge you want.
Honestly, all three of those are VERY GOOD deer cartridges. 30-06 will allow you to hunt with heavier bullets if you go after Moose or Elk is it's best advantage. If you are only gonna hunt deer, the .270 is hard to beat as well.
I would figure out what rifle you like, if you can get it in .280 Rem, I'd jump all over that. If not and you can only get it in 270 or 30-06, you will still have an excellent deer rifle.
Good luck, buying new deer rifles is always fun!!