Like others have said, it all depends where you'll be. If you're in Downtown proper, there's a Starbucks in the Amway Grand (across the street from a Biggby, if you're so inclined).
I've got a rub against Biggby coffee (individual location and corporate). Had a customer service issue that they never resolved, so I vowed to never go there again (and can't in good consciousness recommend it to you). Besides, they're grossly overpriced when compared to S'bucks. Several Meijer locations also have Starbucks inside.
Not too far from the City Center, just down Fulton between Grand Valley's downtown campus and John Ball Zoo is The Bitter End (yelp.com/biz/bitter-end-…)--my favorite coffee shop in GR and beyond. It fits more of your classical definition of "coffee-shop" complete with a book exchange shelf, board games and baristas who rank high on the "interestingness" scale. It's open 24/7 and attracts a sizeable college crowd after midnight. Free WiFi.
If you're hungry, they have Syran-wrapped bagels, muffins and the like. Definitely check this place out if you've got the time. There's parking on the side of the road and in a public lot across the street.