Barcelona day tours

While in Barcelona for a few days on a business trip, we have been given the option to go on some 1/2 day group tours. We will have 2 full days on which to do these. A third day we will travel to Montserrat Monastery and the Cordnieu Winery. We have to choose which of the group tours we want to participate in ahead of time. We don't usually like group tours, although I know sometimes they are the best way to get a good overview. Here are our choices (all are 31/2 or 4 hrs. long):

1)Gothic Quarter and Las Ramblas
2)Gaudi tour
3)Gothic Quarter and Picasso Museum
4)Spanish Village Shopping
5)Sitges

We will be staying at the Hotel Arts. Would we be better off hitting a few highlights venturing out on our own from the hotel? Also should we factor in some time to just enjoy the beach?

I'm really interested to hear people's responses. I hadn't thought about doing tours in Madrid or Barcelona. Is it a good way to see things? (I assume they do some in English, right?)
Does anyone know of any good ones that aren't too long and also aren't that expensive?

With the Spanish Village Shopping tour, I am assuming that is Pueblo Español (what's the real name, the catalán one???), a re-created village of architecture from throughout Spain. I was not really impressed with it. The only thing to do there is shop and eat overpriced, bland food. So if you decide to take a tour, my personal suggestion would be to not do that one!