Maybe Drew B. will chime in. He lives next door in Barnstable. Send him a PM, he doesn't check in as often as he used to.
I always enjoy Sandy Neck in Sandwich - not too far away, as is Bass Hole, both on the Bay rather than Vineyard Sound. The (photographic) problem with Hyannis is that it serves as the hub of lots of activity, both tourist oriented and local commerce, given that it's the town with the train, the hospital, the ferries, etc. If you're into American kitsch, it might be a great place; I tend to head out to the beaches and preserves. Have a great time nonetheless. Cape Cod is crowded, frantic, hot (away from the beaches) and a bit crazy in the summer, but beautiful in spite of it all.