I should clarify that I can only speak for Boston, since that's where I'm from.
Of any of the bootcamps, the most unemployed people I've run into came through General Assembly.
GA sets up its program to really instill an unearned level of confidence in the students, after they attend an extremely short program (10 weeks).
Many of them are super underprepared and have extremely weak portfolios but believe they're totally ready to be hired.
This is all obviously anecdotal - but i can say i've looked at least 50 portfolios that have come through there and 95% fall into this category.
Also, they really love their "group projects."
It's cool to work collaboratively, and a great skill, but when I see a portfolio with a project that's from GA - and someone labels themselves as "Project Lead" I just can't take it seriously.
You can rarely tell who did what – three portfolios will have the same incredible illustrations, but they're actually from a fourth person who contributed to the group.
No bootcamp is perfect, but I couldn't suggest GA.