Mossberg has a combo field/deer shotgun at a decent price (~$350). For a deer only rifle I would go with a .243 or .270 but if you can shoot a 30-06 then you will be able to use the same rifle for deer and bigger game like bear. Savage, Rem have nice rifles.
The question is where are you going to shoot and at what distance. I am in the Northeast and most deers are taken at 100 yds or less. In this situation any legal calibers will do the job provided you can put the bullet in the right spot.