Google Analytics. It’s a great place to start (and easily stay).
“But are their others out there?” Yes, indeed. Both real-time and otherwise.
A perk recently with Google (there are more arguably significant perks) is they just updated their design. For those of us who like something to look pretty and work well, it’s kind of a nice combination.
It’s definitely fun to learn some of the background behind cool products like Google Analytics. Paul Muret left a note to tell the story on Urchin’s landing page for it’s final days (March 2012).
Here’s to more adventures with Analytics!