Shylock is an alien and an outsider - a Jew in Christian society. Shylock, although he does not have that much stage time, is the star of The Merchant of Venice - he has all the best lines. His key speeches show his humanity. He is a living, breathing human being, with feelings and emotions just like everyone else. He is a human, not a cur. Played the right way, the play shows why Shylock ended up filled with hatred and revenge - because of the way he was treated by Christian society. Shylock, for me, is a sympathetic character, whom you empathise with and feel for. Let us give it up for Shylock!
This is Mychael Barratt's take on Sherlock.
Picture credit: http://www.ponyhide.com/mychaelbarratt/shakespeare.html
And this is a photo of Henry Goodman as Shylock in the National Theatre production from 1999. Henry played Shylock as a sympathetic character in the vein that I have outlined above. Henry is 100% authentically Jewish but also 100% sympathetic. Your heart really goes out to him, as an outsider and an alien, trying to make his way in Christian society. He kills off the accusations once and for all that this play is anti-Semitic. It is not, if Shylock is played in the right way, as Henry Goodman does. That is why this is one of my favourite versions.
Photo credit: http://www.culturevulture.net/Television/MerchantofVenice.htm