DiNeros and the Atlantica, both in Cohasset are really good. I'm not a fan of the Red Parrot. I would avoid that place at all costs. It's right in Hull on the beach. Also, for beach food, a place in Hull right on the beach is Barefoot Bobs. They were recently on Kitchen Nightmares. Not sure if that's a good thing or a bad thing since it's apparently cleaned up now.
There's a place on nantasket beach that opened last year or the year before called Beachfire. I've never tried it though. There's an Italian restaurant right on the main strip there also called Bridgemans. It's on the pricey side. The food is okay, I didn't think spectacular, but I'd give it another shot. I liked the ambiance there though and think it'd be a good place to grab a drink at the least. Jake's seafood is really good. That place is always packed.
Thanks. Had a look at Cohasset restaurants on TA and picked up some ideas. I seem to recall Atlantica has nice water view setting.
Bridgeman's has a nice patio now--a good place to have a drink and watch the world go by. I like their food too.