NSQ and NATS are my goto tools for messaging, though NSQ seems more flexible to me because it supports message persistence and also provides NATS-like ephemeral channels for when persistence is not a hard requirement. And it comes with a shiny admin-dashboard, which NATS lacks. NATS is useful when raw performance is a priority.

One thing I do find lacking in both of these queues is support for per-message TTL though, for pruning time sensitive messages. I'm not sure what the performance overhead would be for supporting something like that.