The 7mm-08 is the least powerful and the 7mm Mag is the most powerful.
The .280 is also a 7mm bullet and it is between the two and based on a 30-06 case. The .280 Remington would be a good compromise between power and ease of shooting. The only problem is ammo availibility in stores like the Wal-Marts. If I were mainly deer hunting I would go with the .280 or the 30-06 with the 06 probably getting the nod slightly for elk hunting and ammo availibility(i've had uncles and cousin take quite a few w/ an 06).

Now I have a 7mm-08 and it's been puttin the whitetails down here in WV, but from what more knowledgeable people tell me (as I have yet to make it out west) I should probably take my 06 if I go that way.