... I'm sure some of you know... but aside Sagrada Família, Park Güell, Casa Milà (a.k.a. La Pedrera) and Casa Batlló there are quite a few more works of Gaudí in (and around) Barcelona, many of which are much less 'packed' than these four. Not saying these shouldn't be visited, you should indeed (there's a reason why they are the most popular works from Gaudí!) but if interested in this genious works, you might want to add some of these as well:
TORRE BELLESGUARD - COLÒNIA GÜELL - PALAU GÜELL - GÜELL PAVILIONS
For info, from the fall of 2016 CASA VICENS will be open to the public too. There are plenty more but either are not visitable or too far from Barcelona. For those willing to dine in a very famous Catalan restaurant in the ground floor of yet another Gaudí building -which is not visitable because it's a private building- you should head to Restaurant Casa Calvet which preserves the ambiance of a typical bourgeoise restaurant at the dawn of the 19th century in Barcelona. It's also an excellent resource for foodies as their cuisine is a magnificent example of Catalan gastronomy ;)
Also, jfyi, the name Güell (roughly pronounced "goo-ehl") is so often linked to Gaudí because the Güell family was a saga of very rich Catalan industrialists from the later 1800s which were also patrons of the arts (much like the Medicis in Florence during the Reinassance) and commissioned a lot of work to Gaudí -as well as to other famous architects of the time. Its main patron and benefactor was Count Eusebi Güell --yes, Count ;). I'd like to point out as well that the word 'casa', meaning of course 'house' has a diferent pronounciation in Catalan that in Spanish of course being different languages. In Catalan the 's' is pronounced sibilant as you can hear in this example and if you really want to get into the spirit, Gaudí -a common lastname in Catalonia- is pronounced like this.
Lastly, as a curiosity, did you know there was supposed to be a Gaudí building in New York too?... that would have been Hotel Attraction which you could see imagined here in a sequence of the popular sci-fi series Fringe.
But please, Gaudí -while being the most well known- it's just one of that breed of excellent architects that turned Modernist Barcelona into what it is today. You shouldn't miss visiting other works of art such as Sant Pau Centre Modernista -a stone throw away from Sagrada Famíla, Casa Ametller and Casa Lleó i Morera close to Casa Batlló, Palau de la Música Catalana in the Old City... and many more. And when walking in the street, especially in the huge 18th century Eixample district (pronounced "eh-ee-sham-plah"), simply raise your view towards the numerous Modernist facades and balconies spread across the whole area. Most are private buildings/houses (hence not visitable) but simply admiring them from the street is already a gift.
Enjoy!
Note that despite some of the sites carrying the name Güell attached, they're NOT grouped but spread across the city.