I can't really say which school is academically better or which one you might be more likely to find a job out of (though I've heard rumors that Lansing is the best).
Socially, though, Grand Rapids easily takes the cake. It's pretty easy to find cheap places to live and the Grand Rapids area is one of the best spots for 20 somethings in Michigan. There are numerous excellent bars, a relatively young population, a ton of colleges and universities in the area (including my Alma Mater) and, again, it's cheap! Plus, with so many firms in the area I can't imagine it being super hard to find a summer job.