Bottled water can be even more. You can buy a gallon of bottled water for about the same price as gas, but buy it in smaller quantities and you'll pay. Don't even ask about the microbrews or wines. And drinks are pretty cheap, compared to other things on the supermarket shelf. Check out the per-ounce prices stores post on many items and multiple by 128.
More specialized liquids move the bar even higher.
Even things people normally buy by the gallon cost more than gas. Such comparisons are, of course, limited. With liquids other than gasoline, you're generally paying for a container. And gas prices have risen much faster than the other products. There are a few liquids still cheaper than gas.