Besides the gas powered garden roto tillers, and the manual ones, there are also the electric tillers. Those allow you a hassle free tilling without ever worrying about refilling the tank with gas, or other related stuff. You also don’t have to worry about the gasoline smell, and loud noise that gas powered rototillers have.
However, electric tillers have their disadvantages as well. due to their small size and light weight, they can not be used for tilling in never before tilled soil. In addition, electric tillers also need a power cord for electricity supply, which at some times can be a real pain in the ass.
All in all, electric tillers are good for tilling in previously prepared soil, as well as for smaller gardens.