Second set of Merlin post-finale recs
Time and Tide by srin - M/A, 1700 words. Arthur finds a way back.
The Reincarnation Situation by cait_roswen on AO3 - M/A primarily, 16K words. I liked the premise of this one quite a lot - that Arthur and Merlin only remember who they really are once a year.
An Answering Ripple by mellacita - M/A, 2600 words. Snapshots of destiny.
Visiting Hours by pipelliot on AO3 - M/A, A/G, 2600 words. A bit of past-life tourism, very poignant.
Brought Your Heart to Me by popfly on AO3 - M/A, 3580 words. More past-life tourism.
And if you are looking for fanart to tide you over, or vids, here's a couple links for you:
This reblogged post on my tumblr contains links to art and vids (and fic).
Goss has linked to several pieces of post-finale art, here.