I'm making another batch of my super-awesome limoncello. It takes 90 days to make, but the result is good enough to make your panties fall off.
I follow the recipe from LimonCelloQuest.com, which yields a superb result. I triple-filter my Everclear. I use the best lemons I can find. And I wait, and wait. And wait, anxiously. It will be done mid-October, just in time for my wife Jamie's birthday. :)
Honestly, try making this recipe. The hardest part is finding the glass jar to let the liqueur age in. Once you have that, the rest is easy. Except the waiting part.