Looking for a cost-effective battery

I am searching for a no nonsense cost effective battery that will fit in my 08 ISF's battery compartment and easily fit the stock strap down system that holds the battery in place. I've heard red top, yellow top, size 24, etc. I just want a battery make and model that I can replace without modification. No need for extra amps or to necessarily lighten the weight much. Just don't want to go back to dealer to get a stock and therefore save $. Any help?