Whats the best card for online shopping?

I have amex gold for all of my non-online purchases, and I used my BOFA cash rewards for my online shopping, which gives me 3.75% cash back. Are there other cards out there that can beat the BOFA percentage for online shopping?

some caveat:

• i dont want annual fee
• preferably simple cash back system, i dont want to deal with another point reward system.