There is always a lot of fuss over which 99s are the hardest and which are the easiest. Some are fast but cost a lot of money, some are slow but make money, and some are somewhat in between. This will be a comprehensive list of all 99s in Oldschool Runescape ranked easiest to grindiest. Hopefully, whether you are going for your first 99 or trying to get that max cape, this list will help you find the easiest 99 for you.
1. Prayer
Speed: Extremely Fast Cost: Very High Grind Level: Low
2. Herblore
Speed: Extremely Fast Cost: Very High Grind Level: Low
3. Crafting
Speed: Extremely Fast Cost: Very High Grind Level: Low
4. Construction
Speed: Extremely Fast Cost: Very High Grind Level: Low
5. Ranged
Speed: Extremely Fast Cost: High Grind Level: Meh
6. Cooking
Speed: Very Fast Cost: Low–Meh Grind Level: Low
7. Firemaking
Speed: Very Fast Cost: Low–High Grind Level: Low
8. Magic
Speed: Fast Cost: Very High Grind Level: Meh
9. Fletching
Speed: Very Fast Cost: Low Grind Level: Low
10. Smithing
Speed: Fast Cost: High Grind Level: Meh
11. Thieving
Speed: Meh Cost: High Profit Grind Level: Low
12. Hunter
Speed: Meh Cost: High Profit Grind Level: Meh–High
13. Fishing
Speed: Meh Cost: Low Profit Grind Level: Meh
14. Woodcutting
Speed: Meh–Slow Cost: Low Profit Grind Level: Meh
15. Slayer
Speed: Meh Cost: High Profit Grind Level: Meh
16. Mining
Speed: Meh Cost: Medium Profit Grind Level: Meh–High
17. Strength
Speed: Meh Cost: Variable Profit Grind Level: Meh
18. Attack
Speed: Meh Cost: Variable Profit Grind Level: Meh
19. Defence
Speed: Meh Cost: Variable Profit Grind Level: Meh
20. Hitpoints
Speed: Meh Cost: Variable Profit Grind Level: Meh
21. Farming
Speed: Slow–Meh Cost: Variable Profit Grind Level: Meh–High
22. Runecrafting
Speed: Slow Cost: High Profit Grind Level: High
23. Agility
Speed: Slow Cost: Nothing Grind Level: Extremely High
This concludes the list of easiest 99s. Hopefully this provided you with some good information. Good luck in Gielinor!