Mining without a doubt.
I like how half of you didn't even read the OP lol.. Easy +post count huh guys?
Farming, because its extremely slow. Construction would be up there as well, cost al ot of cash, its slow, and to be honest, having 99 construction isn't worth it unless you spend your entire day at your house in a party world.
runecrafting
Runecrafting is so easy, I got 48 in one day dude.
The hardest one personally is slayer.
READ OP!
And lol? 1-50 is easy in any skill. Runecrafting is horrid at high levels.

