Irish Pubs in London: Where to Celebrate St. Patrick’s Day

St. Patrick's Day is upon us, so where will you be celebrating tonight? London has an amazing amount of Irish pubs, but how do you know if you're going to a good place for a craic (as the Irish would say)?
Check out these five recommendations:

• Waxy O'Conner's
• The Tipperary
• The Porterhouse
• The Arbitrager
• Ryan's Bar