whats the best gears to put in my 2004 v6 3.9 automatic

[comporange2004]

i have a 2004 v6 automatic with 79,000 miles on it. it has the stock gears now, i dont want to make a big jump is size. i drive the car everyday to and from work so i want to keep it good on gas but i would like to wake it up a little,its great after it gets going.i just need it to get going a little faster...