You have come to the right place. Here on Computer Hope. Tthere are lots of experts will give you free advice. First, you need to supply some additional information about your situation. Most importantly, where do you live? Are you inside the United States or Canada? Or are you in Europe, the middle east or Southeast Asia? Each of those areas as different kinds of Internet services available.
If you want best bandwidth, the best would be to go with a satellite system. But that is rather pricey and is not needed in most parts of the world.
As you know, DSl L is sent over standard telephone lines for a limited distance and this restricts the maximum speed to somewhere around 10 or perhaps 15 Mb per second. In practice, the speed in some areas is as low as 3 Mb per second. It varies a lot. It can be as low a 1.5 Mega bits per second.
As for cable, it is by its nature capable of very high bandwidth. You could easily gets bandwidth of over 30 Mb per second. But not always.
An alternative in some communities is a form of wide area Wi-Fi. I don't think that's the right name for it, but I recall one service I had once the I could pick up the service on my wife router but I was not able to use it because it was a VPN. So that company had their own receiver and modem that they would mount on a pole outside my house and it provided really great Internet connection with very high speeds. Those kind of installations tend to be very localized and are not available in all communities. You have to check locally to see if somebody has that in your area.
Regulations involving telecommunications vary from one country to the other. There are rules in place that allow customers to buy their own equipment and just pay fees for the service. In many cases, that's the best deal you can get.
Here in the United States in some areas, it's possible to get suitable DSL service for $15 a month. If you have your own DSL modem and router.
Another alternative used by some is to the use a data plan that comes off the cellular service. If there is good, 3G or 4G cellular service in your area, that could be a good choice. If you have to check locally to find out what the current prices are.
Check around with your neighbors and friends and see what other people are doing. There may be in some communities, some kind of five community effort to bring free Internet into certain areas of a city or village. That might be worth looking into. In some areas.