Are there any big box chain stores like Walmart of Best Buy in Pleasant Valley?

Only if you consider a place like Family Dollar a big chain store, and I wouldn't. There's no Wal-Mart within a number of miles of Pleasant Valley and the nearest Best Buy would have to be in the Poughkeepsie Galleria, at least 15-20 minutes away. The big retailers haven't found their way to Pleasant Valley yet.

There is a K-Mart in Poughkeepsie near Town Hall on Route 44, and I believe there's also a Big Lots near that. Those are probably the closest ones.