Real-time apps, are using websockets, vs server-sent events, vs good-old http polling?

For all you tech makers out there! What are you using to make your apps feel real-time if you have a use case like that? Websockets, SSE, or http polling? Or maybe you leverage a 3rd party company with a wrapper around one of these technologies? I'd love to hear anybody raving about anything or horror stories as well! Thanks in advance!