Joules Kowalski
Joules Kowalski reviewedHabiticaCreating habits and achieving goals, gamified.
 RecommendedPros: 

* It's the most fun I've ever had with a to-do list

* You can "quest" with friends to gain support and accountability

* It's free

Cons: 

* The UI isn't always the easiest to use, but I still think it's definitely worth it for what it provides

I've been using Habitica (previously Habit RPG) for years now. If you haven't tried it, you should. It's a fun and easy way to turn your life into a game and feel like you're winning at it. :D

Pro tip (from personal experience): If you find yourself with a lengthy task list that you never finish and just feel guilty about, scrap it and start over with smaller, actionable items. Life should be fun!

Joules Kowalski has used this product for one year.