Crowed and dirty sums up the Venice Beach scene for me not the eclectic scene portrayed in travel guides. The tourist traffic getting there leaves one expecting a whole lot more than this area can deliver. The famous outdoor Gold's gym had 2 people working out and looked more like a scene from prison 101.
Unique Suggestions: If you can avoid driving in (i.e. park in Santa Monica and bike or blade in) do so for a better experience but keep in mind the main strip with shops is too busy to blade or bike.
Fun Alternatives: Santa Monica has the same bike trails for biking and blading, is less crowded, and just as "artsy"