This place is absolutely packed on the weekends. If you are scared of crowds you may want to save your trip for a weekday. But, there will be far fewer vendors as well.
The selection of flowers at Pike Place Market is unbelievable! The prices are rock bottom as well.
You can always find street musicians playing at the market. Drop a buck or two in their box if you have enjoyed the entertainment that they provide. Seattle seems to have a lot of starving musicians.
Not only are the street performers entertaining but so are many of the vendors. Probably the most entertaining are the fish mongers at Pike Place Fish Market. Both the jokes and the fish are always flying at their fish stand.
You can find a lot of strange stuff at the market. One of the strangest has to be the Market Theater Gum Wall. Said to have started in 1993, people have been sticking gum to the walls of this alley making it Seattle's germiest tourist attraction.
I may not be a fan of big cities but I would have to say Pike Place Market is a very good starting point for any vacation in Seattle, Washington.