Happens in Sitges: Sitges International Film Festival (around October), Vintage Cars Rally Barcelona-Sitges (around March), Carnival (around February), Gay Pride Parade (around June)
More information:
http://www.visitsitges.com/en/
http://www.gencat.cat/diue/doc/doc_23336176_1.pdf
http://en.wikipedia.org/wiki/Sitges
How to get there from Barcelona
Also near by and worth visiting: Vilanova i La Geltrú, Vilafranca del Penedès
Other videos:
Sitges, the Catalan answer to St. Tropez
Video: © Joe Journeys
Source: http://www.youtube.com/watch?v=vbIxwBfAm3M