I also think that bounty campaign plus community airdrop is the best way to distribute coins if you won't have an ICO. To avoid multiple accounts, you can make a few requirements for participants to get airdrop, like link their twitter, facebook and bitcointalk accounts.
Any well managed, successful Airdrops you would suggest that we check out and learn from?
I would suggest to check Rebellious airdrop from the end of last year, because IMO they did it the best possible way and create loyal community.
Yes it is the best way to distribute coins the bounty campaign plus community airdrops. Well for me we can do both.