Originally Posted by Reindeerflame
Probably the Regent is fancier in terms of certain offerings that appeal to classic business travelers from the states, but the Adlon is sheer understated class with historic relevance, and was recently ranked as the best hotel in Germany and 5th in Europe by one survey (Travel and Leisure). Berlin hotel prices are very modest compared with other world capitals, and usually include taxes in the quoted rate.
Thus, while many prefer other hotels, I really enjoyed the Adlon, where I have stayed twice.
Once, when the pleasant doorman asked if we needed a cab, I (almost apologetically) responded that "no, we're [just] using the S-Bahn", thinking that might be viewed as a "crime" for people staying at the Adlon. He responded by saying "naturally...why not?" which was very reassuring and unsnobbish.
Last year, and probably this year, I will stay at the 5-star (possibly in name only) Swissotel on the Kudamm, which has a great location in old West Berlin. Quoted prices with prepayment: 100 Euros per night for July. That won't even get you into the Travel Inn County Hall in London, which is probably the equivalent of a 2-star.
Thanks for all of the responses! Speaking of London, last year I stayed at the Le Meridien Piccadilly (which was rated by expedia as 4.5 stars) and I thought it was the nicest place I had ever stayed at. I paid $183 a night, plus tax.