There is no such thing as best farming site or way to get eso gold. The best way to accumulate gold depends on many factors: class, time of farming, solo or with party. Basically, it is all about the convenience.
Example: there is a farming site where you can gain 100k gold per day. However, it is only possible with party which the items will be distributed equally after the hunt. There are solo areas where crowded by people and only efficient during a certain server time.
ESO gold – Convenience
The convenience is the most important factor. You may be able to acquire good loots but you are having a hard time killing a monster. It is pointless.
When choosing a farming site, consider these factors: monsters are easy to kill, rewarding drops and not overpopulated. If you insist on the overpopulated map, find out the best time where people disperse from the area which is less likely because they are zombies.
The Market
The market is a very important factor. You don’t want to collect items that would not be wanted in the market. You want to collect items that are highly demanded in the market. However, the place where you could get these items is usually overpopulated.
It is like you are in a big pond with other players and spot where expensive fishes dwell are full of fishing poles of other people. And if you are under level, you won’t be able to compete against other players.
Try different kinds of stuff, although it is kind of pointless because there is only one or two ways to get farm.
Verdict
ESO gold is not always on the popular spots. It is usually on unique places. However, there are scarcely unique places in MMORPG. Unique places only exist during a new patch; take for example the thieves’ guild. People often buy eso gold items in such places.