Which Hot Water Heater Is Best?

Currently there are over 10 different ways to heat up your water that I know of. They are listed below, along with some notes. I spent a bit of time looking into all of these as we wish to replace our own costly oil hot water heater.

Natural Gas Tank Hot Water Heater - Natural gas is a good environmentally clean and economical alternative to fuel oil and propane. Unfortunately, natural gas is not available in many rural locations.
Propane Gas Tank Hot Water Heater - Propane is clean burning and efficient and available nearly everywhere in the US. The drawback of propane is that its price correlates to crude oil prices and thus may increase greatly as oil prices increase.
Oil Tank Hot Water Heater - Oil hot water heaters are one of the best performing with respect to quick recovery times, but the skyrocketing prices of #2 fuel oil has now rendered them as a non-option. In our household, we are now spending over $120 per month on our hot water heated with oil!
Electric Tank Hot Water Heater - For those without access to natural gas, an electric hot water heater may be your best option since electricity may be generated with a variety of different fuels and methods. Also, electric hot water heaters offer simplicity and safety. Note that recovery times for electric hot water heaters are as low as 10 gallons per hour. So you should go with a larger tank size. This is the option we chose to take.
Solar Panel Heated Tank Hot Water Heater - With this system, solar heating panels heat your water, even in cold northern climates. These typically price out at over $6000, but after searching around quite a bit, I found a solar hot water system for $2500.
Heat Pump Water Heater - In this system, a heat pump extracts heat from your surrounding interior and heats your water. This is a great system for warm climates since it also reduces your AC cost since it cools and dries your air. In colder climates, this type of water heater will increase your heating costs in winter months.
Electric On Demand Tankless - This hot water heater heats water as needed, and thus does not require a large tank. This is a good option if you have the electrical system needed. This type of heater will typically draw 100 Amps by itself! If you only have 100 Amp service, some major updates costing perhaps thousands of dollars will be required.
Natural Gas On-Demand Tank less - This hot water heater only heats as needed, eliminating the need for a tank. This is a great option but will cost about $1200 plus installation for a whole house heater.
Propane On-Demand Tankless - Similar to a natural gas on demand hot water heater except fueled by propane. And propane prices will increase as oil prices increase.
Use of Wood Heat or Other Heat to Preheat Your Water - This is pretty much a DIY type project for those with some plumbing, building, and design skills. There are some plans for a wood heated water pre heater here.
UPDATE: I was able to recapture some of my wasted heat from my oil hot water heater to heat a temper tank that then preheated my water - read about my hot water preheater here.
Alternative Solar, Such as Solar Showers - You can build your own solar shower for as little as $30. I did! You can get the free plans for this solar shower here. There are many other plans available on the internet as well as some fairly fancy commercially built solar showers.

We ended up deciding to keep our oil hot water heater while taking measures to cut our oil consumption and costs by 50% or more. Read about how I was able to save on our hot water costs at this page. Natural gas was not available, propane is another dependence on crude oil, and the other options such as on-demand electric, or solar, exceeded our present financial means.