I have always been searching for the best spot and I have discovered quite a few good spots for farming gold in LOTRO, but I never could decide which one is the best. The one I thought that was good enough for a casual player as well as for an experienced one is inside the great hall of Sarnur, near the entrance to Sarnur Keep. The dungeon is filled up with dwarves and cave-claws having around 1900 hit points, very easy to kill. The respawn rate is generated by the number of players inside the dungeon and you may encounter even instant pop at some points. Knowing all these, you could say "the more, the merrier" but you also need to be extra careful so you won't die, to avoid high gear repair costs.
The most important drops that the mobs inside Sarnur Great Hall have within the loot table are the barter items from the dwarves, the Dourhand Crests and the First Age Relics, to be more specific, and the exceptional hides dropped by the cave-claws. You can also get rare single use recipes and some other crafting resources beside the hides, like beryls or undeciphered moon letters.
Depending on the prices of the day at the Auction Hall you can make up to 3g an hour which is not bad for a level 47-48 character.
This spot was my solution to the farming gold in LOTRO problem for a while, when leveling a character, because not only that you get nice loot, you will always get nice XP here.
With the arrival of the new LOTRO expansion, Mines of Moria, I decided, though, to get me a LOTRO Gold farming guide. The detailed maps and locations revealed quite a few "gold mines", spots that I wasn't aware before. Using this guide I managed to double the amount of gold/hour that I was accustomed with.