Hatchards bookstore: 3 times
Sherlock Holmes Museum Store: 4 times (It's on Baker Street anyway, about 2 minutes away from the college)
Fortnum & Mason: 2 times
Hard Rock Cafe: 2 times
St. Paul's Cathedral: 3 times
The Globe: 2 times
Westminster Abbey/surrounding area: 3 times
Regent's Park grounds: more than I can count. Multiple times each day.
The Old Vic: 2 times (second time a bit better than the first)
Lyceum Theatre, trying to get Lion King tickets and then actually going to Lion King: 3 times (I think)
Baker Street Tube Station: At least twice a day, every day.
Walking past Big Ben and the Houses of Parliament: about 100 times less than I would have liked.
Kensington Gardens: 2 times
And then there's places I'd have liked to go back at least one more time:
The British Museum
Stratford (not London, I know. I actually might go back there this week! I'm only about a 20-minute train ride away...)
Bath (also not London)
Buckingham Palace (maybe to see some of the inside come August...)
Nando's (really good chicken restaurant - I think it was Brazilian)
The National Portrait Gallery
And that's all I can think of right now. I won't make a list of things I didn't see and want to, because that could go on forever. I'm convinced that you can never run out of things to do or places to see in London. Even if you've seen it before, being with the right people can make anything fun and exciting. Here's to great friends in the London group and many happy memories!