This scrapheap of abandoned adventures isn't a bad thing in itself -- sometimes a game just doesn't work for whatever reason and it could be worse to plough on when no one's enjoying it -- but it has become something of a joke in our group so it will be nice if we can finish Carrion Crown, assuming that I haven't now ruined our chances.
I don't know if campaign abandonment is a common issue; mxyzplk at Geek Related seems to run through three or four campaigns a year but he may be an exception. My original gaming group didn't really go for long-term play but we did sort of finish a sandbox style Shadowrun campaign -- I say "sort of" because we played until our GM +Timothy Coxon went to university but there was no neat, plotted end -- and we played Dungeoneer until we broke the system, but I'm not sure that counts. I did manage to finish Horror On the Orient Express with the group but by the time we got to the end the players I had were not the same players who started it, so I'm not sure that counts either.
I seem to have the most personal success with Call of Cthulhu -- perhaps ironic given its dual reputation as being deadly for player-characters and being rubbish for campaign play -- as one of the few campaigns my current group has completed is Tatters of the King; it wasn't a conventional finish as the players missed half of the campaign, but they did defeat the cultists and save the world so I'm counting it.
So when Carrion Crown ends in a few weeks -- again, assuming I haven't scuppered it -- and our GM Ben takes a break from running games to do stuff like move house and study for a master's degree I should perhaps run something for Call of Cthulhu, because there's a likelihood we might finish it; indeed, I will be getting and running Eternal Lies at some point. First though, I'm going to have a go at running the new version of The Enemy Within for Warhammer Fantasy Roleplay; I reckon WFRP is close enough to Call of Cthulhu that we've got a fair chance of getting to the end.