how ya makin sure the message queue doesnt crap out when theres a ton of traffic

I'm building out a new microservice setup and using message queues a lot for services to talk to each other. It's really good for keeping things separate, but I'm starting to wonder how reliable it'll be when traffic really spikes. Have you guys found any good ways to stop messages from getting lost or really delayed when the queue is slammed? Also, are there any particular queue systems you like best for when you need to handle a ton of messages super fast and it's important they get through? What are the downsides to those?