We stayed at the Continental Palacete a couple of years ago.
https://www.hotelcontinental.com/hotelcontinentalpalacete/en
It is a bit quirky(!), very pink with a dining room/lounge in the style of Versailles!!! (but the furniture wasn't). However, it was clean, staff were helpful, 24 hr buffet including drinks (alcohol included), you could take a couple of bottles of water out if going out for the day etc. I'd stay there again no problem. There is a taxi rank outside the door and the fare to the cruise ship when we were there in 2008 was €21. Its just north of the Placa de Catalunya (about a 5 min walk), but its sister hotel (the Continental) is on Las Ramblas if you'd rather be in the heart of things.