The annual Corktown (Detroit) 5k is only about 6 weeks away. If you've not run this race, definitely try it. You run the St. Pats Parade route, so the streets are lined with people drinking beer and cheering you on. The cool part about the race is you get a free (Michigan brewery) beer at the finish line. It's worth sticking around to watch the parade (or people watch). The main drag turns into one big party during the parade, a really neat atmosphere, especially for that stretch of Detroit.
I've done this race the last few years, I'll probably go for it again. I'll definitely need to kick in some speed training if I want to compete with my time last year (23:24). It's pretty easy to sprint 3 miles though, especially when you know the reward at the finish line!