Safari 10.1
Safari is a great browser and I'm sometimes surprised at how huge Chrome's mindshare among developers is. Every time I try Chrome out on my Mac I end up running screaming back to Safari. Safari doesn't choke on tons of tabs, it doesn't eat battery and memory for breakfast, it's never started autoplaying videos when I open a tab in the background, it's got support for picture in picture video which is my most used new feature of OS X in ages, and is fast fast fast.