I've just spent hours on the Chicago one. It's funny that we have been here almost 7 months and I have never actually been on it.
It has a great list of events that you can then click a button and quickly add to your Google Calendar. Mine syncs with my iPhone so I've been adding different events on so I won't forget!
I see lots of visits to different farmers and flea markets in my horizon. Not to mention the free concerts in Millennium Park. So excited!! Next weekend is Maifest in our neighborhood.
So what is your favorite website to find events in your city?