When I was growing up the Beach Boys were considered terminally uncool; a joke, in fact. It wasn't until college that I even began to appreciate their accomplishment.
Having said that, I found and still find Pet Sounds somewhat overrated. Sure it has some great songs on it, but it doesn't hang together as one of the greatest albums of all time for me, despite its seminal role. Love You, however, has long been a personal favorite and I still think it's one of their best albums. It always amazes me that even some fans underrate it.
A couple of my favorite Beach Boys songs: "I Get Around" and "Good Vibrations"---obvious choices perhaps, but sincere. And yes, "Good Vibrations" has been overplayed to within an inch of its life, but it's nevertheless great, and one of the best songs of the decade.