My friend & I were tying out the various ways mentioned above, and while they all work, they're insanely tedious (& tiring in the case of the post grab one)
This is very similar to Dakotathrice's hunter medal solution.
But instead of hosting 1 on 1 fugitive and suiciding, we thought: "what if we had a group of people taking turns suiciding as the fugitive?"
(Th following paragraph is now irrelevant with the discovery of The Dark Town map)
Have a session with 8 people, take turns hosting (host is always fugitive). Settings: have 9 hunters not 7 (you often get 1 or 2 randoms). Equip rocket launcher (use grenades for suicide, unless you get plasma grenades, in that case rocket yourself). Time & stage don't matter too much, but if you all have the free dlc maps then you'll get fewer randoms.
You only earn 1300-1400 per match, each match taking 30 seconds (or less) But you're earning xp nearly every round, not every other round. Plus you all get the hunter medal in minutes
June 27, 2015 edit. Island 902 *was* the fastest, each map took 5-25 seconds for fugitve to jump into the water, match instantly ended.
However my friend Hords discovered DarkTown (push left once on map select) is even faster: fugitive spawns next to dummy grenade. Press B to pick it up, left trigger to throw, suicide, match instantly ends. No need to change weapons, so you save time creating the match.
Using dark town each map lasts 5 seconds.
Yes, like my wedding night
*forgot to mention: ranked match -> create match