We just went to waterfire a few weekends ago, we ended up at Luxe Burger, which was really great, loved the atmosphere, great music, wish we stayed a little longer. After waterfire we went to Parkside? I believe, lots of dishes were rotisserre - pretty good, I enjoyed my chix, my dining partners loved their fish, but not their seafood pasta, that had a cool vibe too
220 W Housatonic St, Pittsfield, MA 01201
5 Memorial Blvd, Providence, RI 02903
This question comes up here periodically. It all depends on what you mean by "accessible". If you're willing to walk 10-15 minutes to/from dinner, then you have much of the city at your disposal, and should just search this board for Providence, pick what you like or ask based more specifically by price range or cuisine ("reasonably priced" means different things to different people.)
If "accessible" means "can I sit and eat and see any portion of Waterfire from my table", there are very few options -- others can correct me if I'm wrong, but I'm coming up with Cafe Nuovo, which has mixed reviews here and is packed on Waterfire nights, but has the closest seating, some of it outdoors; Ruth's Chris, about which not much needs to be said; and the Waterplace restaurant on the other side of the basin, which also has some outdoor seating, but has never been mentioned here and has pretty negative reviews on Yelp. That's it.
The thing to know about Waterfire is that it's not designed as a sit-and-watch experience. It's for walking around. You can stroll and sit for a bit here and there, or take one of the gondolas if you want to splurge, but you really need to experience the whole length of it. And if you really want to keep the budget down, there are street food vendors in a couple of places.
It really depends on the type of food you want. There isn't much you can't get as far as good food goes in downtown Prov. On a nice night most places would be a pleasant walk from the Water Fire, no need to stay too close.
My top pick when I go to Providence is to head up to the Hill, but I have been going for about 20 years, so a lot has to do with nostalgia. So many good picks up there when it comes to Italian food!