Well, let's try ranking them and then discussing. My opinion? 1. Summoning. Whether you do it with bursting rock lobsters, it still takes time and is not buyable. 2. RuneCrafting. Entirely unbuyable and can take longer than summoning. 3. Farming. It's difficult to manage all the crops at once, and even more difficult to get without losing money. 4. Slayer. It's like all the combat skills rolled into one. 5. Tie between fishing and agility. Good old fashioned grinding. 7. Woodcutting. It's nearly the same thing as the other two, but takes a shorter amount of time. 8. Mining. Not buyable, but slightly faster than these others depending on how you do it. 9. Hitpoints, the hardest combat skill to get 99 in. 10. Defence, just about the same as the next two but takes just a BIT more time. 11. Attack and strength tie here. 13. Magic. Buyable due to alching, but also can be done with a profit. Any alching is considered buying the skill, whether you lose cash or not. 14. Ranged. This skill can be the fastest 99 depending on how you do it. 15. Hunter. Another grind, but not a particularly long one. 16. Thieving. Yet another grind, but a VERY quick one in comparison with the others. And now we're into the buyable skills. 17. Prayer. VERY expensive, takes tons of attention as well. 18. Herblore. Less attention, plenty of expense. 19. Construction. Very expensive and takes a fair amount of attention. 20. Smithing. Takes plenty of attention but less expensive. 21. Fletching. Slower than cooking and takes more skill to manipulate the market to break even. 22. Cooking. Really just extremely unskilled. Now your turn, let's discuss!