Take a look at your chart for the area you've described. That's where you'll find the answer. The city with the largest, most sail-able inland lake (connected to Lake Michigan by channel) is Muskegon.
The downside of Saugatuk or South Haven, for example, is there's no place to sail when Lake Michigan's too rough. Having a good inland lake makes a huge difference in how often you'll be able to use your boat, particularly a boat in the trailerable size range.
There are multiple marinas in Muskegon with available slips, and opinions would vary on which is best simply because people have varying criteria. We're very happy at Hartshorn marina (it's city owned). They also have mooring available with a convenient dinghy storage and lauch area. In addition to the regular marina with the standard amenities like showers, shore power, and water, they have a lower cost area with slips for boats under 27 feet (approx) but without shore power and water.
Other than Muskegon, I would agree that Lake Macatawa in Holland is nice, and White Lake is nice.
For sailing, I'd have to say, emphatically, that Muskegon is the best sailor's port on Michigan's West Coast.
Muskegon is not necessarily the best port to cruise to and stay over, because the municipal marina is not within walking distance of stores and restaurants.