If you're looking for a good fanfiction ending then I highly recommend this one. It's dark and desperate, but it takes your actions into account and reveals the Reapers without turning them into a joke.
Awesome. Although not as good as my Shepard uses Cerberus tech to revive Macgyver. Who then creates a device out of a toaster, duck-tape, a banana, and 69 paperclips that instantly deactivates all reapers. Then Macgyver and Shepard go on an epic journey to sleep with a female of every single race in the galaxy.
