I absolutely HATE ethanol for a variety of reasons.
1) Ethanol contains significantly less energy than gasoline does. Burning one gallon of gasoline will net you 114,000 BTU, while burning one gallon of pure ethanol will only net you 76,100 BTU. So ethanol contains 33.246% less energy than gasoline does. E85 contains only 81,785 BTU per gallon, resulting in a hypothetical gas mileage decrease of 28.259% from 100% gasoline to E85. Moving from E10 to E85 will net you a loss of 25.791%. So if E10 is running you $4.00 a gallon, and you'll save $.50 per gallon by switching to E85, you'll be saving 12.5% per gallon, while burning 25.791% more. You'll actually be losing money by burning more fuel per mile.
2) Ethanol dirtys up oil like no one's business. Toyota (my employer) recommends oil changes every 10k for vehicles running synthetic and every 5k for vehicles running conventional. For Flex-Fuel vehicles running E85, the recommended interval is 2,500 miles. Running E85, you'll spend quite a bit more on oil.
3) Ethanol is hygroscopic and miscible in water. Water+fuel=no good.
LPG isn't much better. It looks like a gallon of LPG will run you around $4.00 or more. LPG contains 84,300 BTU per gallon. So unless LPG burns significantly more efficiently in a IC engine, that too is a waste of money.
CNG is running in the $2.50 range per gasoline gallon equivalent (GGE). By my calculations, CNG yields 114,003 BTU per GGE. So it's looking like with current prices, CNG is the only cost effective way to go.