Start at The Tank. Click on Tanklets. Upper left corner click on red box with white letters “Choosing a Water Heater”.
Steel tank WHs are all made about the same. You could get a really good one or really bad one from the same maker. But if you are willing to change the anode +/- 5 years depending upon water quality (and if you soften) then a steel tank water heater will last YEARS! You can get anodes and other neat stuff from this site.
If you don’t do maintenance then depending on water quality you replace the WH every 5 to 12 years.
Buy a Marathon which is pricey. The cheapest place I’ve found to buy Marathons is http://www.chec.coop
Which size to buy: If Time of Use rates are available you can get a large tank, heat off-peak only and recoop the cost of the larger tank relatively quickly. I power my 105 gallon Marathon off-peak only. I have all the hot water I need for less than $24/month.