I'm looking for a good guided Gaudi Art Tour in Barcelona. Any suggestions?
Start with the official Barcelona TI website. The TI's own tours are usually very good. Runnerbean's tours are highly recommended.
I took the TI's modernism tour in 2016 and enjoyed it. Understand that you will not go inside any of Gaudi's buildings; they have high admission charges.
What was included 3 years ago was a brief (about 15-minute) visit to the modernism museum that's relatively near the block of discord. I liked it. I would have preferred to have a bit more time there, but the museum is small, and I remember thinking the regular admission charge seemed a bit high (maybe 10 euros in 2016??).
The Museum Nacional d'Art de Catalunya has quite a good modernism collection, mainly furniture and decorative arts.