AWS re:Invent was a really good one. I attended the 2012 and even got to speak, I missed the 2013. 2012 had good content and was well organized. I didn't make 2013 so not sure about this year.
sxsw? More for pure design but they had some good tech talks last year.
#protip if your going to leave your job, always do it the week before you go to SXSW. You will have fun, renew and make new friendships, get a wide perspective, likely walk away with a bunch of full-time or contract leads and have fun (its worth saying that twice).