I don't remember how long ago it was, but it was an AURORA event, so that should give you an idea (in before WTFisAurora). I am not exactly sure why it was my FAVORITE as it was a bitch and I was almost killed a million times, but it was fun and full of RP goodness.
APEX was involved in some sort of Inotech (or some variation of that name) test of what was then a prototype jump drive that could be fit on non caps. Vendrin, myself and I think Tek Avalos of APEX were in a Navy Raven and a couple of Navy Cerbs, and there were a few Aurora actors there.
yada yada yada The thing exploded and the Aurora folks put me, Ven and Tek each in a different point in nullsec, in our Navy ships, wishing us our best to get back.
I, ironically or not as this was before I decided Usagi would be a bad girl Gurista, ended up as far back in Venal as possible and while it took me I think two full days of ducking and dodging, managed to get that Cerb back in one piece.
Just rings as my favorite because of, what I thought at the time was, the level of involvement CCP wanted to have with the players. Plus I decided to annoy some nullsecers in local by staying IC.