At first glance, it may look like the Citi Custom Cash Card would earn you the most cash back since it earns elevated cash back on your top spending category each billing cycle. However, its bonus category spending cap means you may earn more rewards with the Citi Double Cash Card’s unlimited cash back. The Double Cash card might be a better pick if your biggest expenses fall outside the Custom Cash Card’s 10 bonus categories or if the $500 spending limit for one category per billing cycle would hobble your rewards potential.