SUNY-Binghamton Reunion/Homecoming Weekend
I would suggest the P.S. Restaurant in Vestal, which serves French/Thai food. I haven't been to it recently, but it's located in a shopping center that's part way up a hill, so I don't think they would have suffered any flood damage.
100 Rano Blvd Ste 8, Vestal, NY 13850
Yes, the floods will definitely complicate your search for restaurants, since I know the south side was hit pretty hard, and I'm sure many restaurants downtown suffered some damage as well. I'd definitely say call ahead before you plan anything.
I can't really help with fancy dining, since I was on a grad student budget when I was eating in Binghamton 2003-2007. My favorite places were the Lost Dog Cafe downtown, China Lake in Endwell (authentic Chinese food, served family-style...very homey and affordable, but the absolute best Chinese food I've had), and some of the Italian restaurants in Endicott, especially Joey's for brick oven pizza and Consul's. I've heard that Consul's has opened a second restaurant right next to campus, in that little plaza sort of near Denny's. That may be one of the only non-chain options close to campus.
I haven't had a meal in Binghamton for a few years now (though I do stop for a pizza at Joey's once in awhile if I'm on my way through and have the time), but I found this blog that has fairly recent restaurant reviews. To be taken with a grain of salt, of course, but it seems pretty comprehensive: http://tastingbinghamton.blogspot.com/
China Lake Restaurant
3215 E Main St Ste 2, Endicott, NY 13760
222 Water St Ste 101, Binghamton, NY 13901
Hi from a fellow Binghamton grad! (2004) Unfortunately, much of the south side of Binghamton suffered a great deal of damage from flooding recently. My father in law sent a photo of Number 5 restaurant in particular with a water line well up the side of the building. I'd call them. There's not much action on this board from the Binghamton area so I would check Yelp. While in general I don't find it as reliable as CH, you'll at least be able to see which of your favorites are still around and find some new places too. Have a fun weekend!
Number 5 Restaurant
33 S Washington St, Binghamton, NY 13903