Hmm... The best places I've hiked have been in the Upper Peninsula of Michigan. Most of it hasn't been public trails, but the backwoods near where I grew up. As for public places, Pictured Rocks by Munising in the UP is pretty fantastic--put that into Google Images and you'll see what I mean ;) There's also the Porcupine Mountains and the Estivant Pines, and a variety of locally known spots up in the Keeweenaw Peninsula.
I just moved to the Detroit metro area a few months ago, soo... not much hiking. If you want to find woods, it's pretty much necessary to head north. There are recreation parks not too far way from the city (the closest one that has good mountain biking trails is at Pontiac Lake, about an hour outside of Detroit) but after the beauty of the U.P.--well, that's a tough act to follow.
Where did you hike in California, and why did you decide to move to the midwest?