There are many bounties in this thread - https://bitcointalk.org/index.php?board=238.0. You need to do a specific bounty survey before joining. How to choose good - it should have a currency exchange, a great community and support from the dev team. If i can recommend good bounties for me - PRiVCY bounty program. Another interesting bounty is the STAKER token - https://bitcointalk.org/index.php?topic=4435123.0. It is up to you, which you see "good bounty", it's always a bit like a lottery, you must be lucky.