My wife and I did a big holiday in the UK in 1990 as a final fling before having kids. Our best man was living in Chelsea in London at the time (in the basement flat of the house were George Elliot died) on Cheney Walk. We spent a week in London with a tube pass and buzzed all over the city. Next we boarded a train and took off for Scotland. We went to Edinburgh for a couple of days and then on to Loch Ness. On the way we met a Royal Mail driver on a busman's holiday and I told us about the beautiful train trip to Kyle of Lochalsh. From there we took the ferry over to the Isle of Sky for a quick walk around.
After that we took a sleeper car back to London. We then took a couple side trips to Gilwell Park (Boy Scout leaders that have been to Woodbadge training will understand this one) near Chingford and to visit a friend of my wife's in Herfordshire.
Needless to say, we had a total blast.
As far as food goes, we were on a budget so we usually ate fastfood. We did eat at McDonald's a few times... and were horrifed to find that they charged 5p for a packet of ketchup (over here free ketchup in restaurants is close to a civil right). Whimpie's didn't impress us. The restaurant we ate at the most was a chain that I think is now defunct: Pizza Land. When we were there they were running a special where you could get a slice of pizza, a Coke, and a chocolate sundae for 1 1/2 pounds. This pizza wasn't the best, but you couldn't beat the price!
We had a couple of "tourist moments" envolving food. We went into a London pub and asked for a Ploughman's Lunch like the guidebooks recommended. They looked at us like we were idiots, and we felt half-way ready to agree with them. After awhile they produced something that sorta looked like what our book described, so we could say we'd eaten one. The next "incident" was at the snack shop in the V&A. I asked the person behind the counter for "hot tea" and she replied "What kind?" No one had ever asked me that question in my life. My mind locked up. I thought "What do you mean 'What kind?' you know... Lipton!" Finally I uttered "Earl Grey" only because I in a sudden flash I remembered that it was the type prefered by Capt. Picard on "Star Trek."
I also had a short return trip to London on business in 1998 and got to spend a couple extra days there. It was during Rememberance Day and I was touched by the way they remember their war dead in the UK when such a tradition is almost totally lost over here.