Which is your favourite?
The Rising Sun is one of my favourites and felt like a local pub for workers and the like. Ye Olde Cheese Cheese, Cittie of York, Princess Louise and The Champion for historic and architectural reasons while I think that the Fitzroy Tavern is okay, but greatly overrated (and I was put off by the staff on my last visit). The Dover Castle is quite nice and my hat was still there when I went back for it! I like the location of the George and Vulture, although there was little on the menu for me to have with my diet as not the usual Samuel Smith's menu (and you had to eat to get a drink). Have a look at the back wall of this pub, I found it a little peculiar.
The Earl of Lonsdale is okay as is The Angel (Bermondsey) and The Crown and Sugarloaf. The Anchor is a lively boozer, spoiled by early closing hours. Quite a few Samuel Smith's London pubs have bar billiards tables, which make them a little more unusual then your average JD Waterspoon's "pub".
Hope that helps? It's hard to say which one is my favourite because there are so many good ones and I like different pubs for different reasons and occasions. Also, The Blackfriars is worth a visit (not a Samuel Smith's pub) if you are boozing in the nation's capital.