Plans are firming up for my wife and me to visit Europe in April-May. We'll be visiting several cities we've not be to before, among them Cologne, Vienna and Berlin, and we'd like suggestions for Rick Steves type lodging: small, clean, and modestly priced (under$100)in all three cities. We'll be traveling by car in Cologne so the lodging could be outside the center-city. In Vienna and Berlin we'll be traveling by train and public transportation while in the city, so we'd like to find lodging within 700m or so of a metro/tram stop if possible.
K&T Boardinghouse in Vienna. Tina and Kaled are good friends with Rick Steves. They now have a second location close by their original place, and the price and quality of their accommodations cannot be beat. The location is also great, with the subway under the street in front of their place. They're online.
Pension Sacher in Vienna. Must book months in advance. Very popular.
I usually recommend Hotel Coellner Hof in Cologne. Very comfortable, with a beautiful old world look, fabulous breakfasts, and the location is pretty central. Parking is 8 euro per night. Room rates vary depending on if you are there weekdays or weeknights, but average 75-85 euro per night. http://www.coellnerhof.de/index.php?seitenID=9033&menueID=4896
Berlin is awash with cheap hotels but in my experience the cheapest option there is renting an apartment. Both booking.com and airbnb are popular sites that show aparment rentals in addition to other kinds of lodging. Berlin is really spread out, but there's convenient public transit - either Ubahn or Sbahn - almost everywhere. I've stayed with GoApartments in Berlin in a few locations and while I wouldn't call it luxurious exactly, the price is fantastic and the locations are very central for sightseeing (less so for nightlife) I would also consider the Arcotel Velvet. I stayed in their fancier sister hotel, the John F, but I think the Velvet should be in your price range. I am planning on staying there in the future, as I enjoyed the John F so much and it's such a great location. I really, really recommend staying in the East in Berlin. The huge area referred to as "mitte" is really convienent, but so is Kreuzberg, and Prenzlauerberg is lovely, just make sure you're near an Ubahn stop. Also once you pick a hotel, do some online research and look up bus routes. It's always a little scary to use a bus in an unfamiliar city, but Berlin busses clearly state on electronic screens what the stops are, and I actually found the bus to be more convenient for getting around than the ubahn, because I would always have to transfer on the Ubahn line, whereas the 42 bus went direct to where I wanted to go. Something to consider! If you're just buying an all-day or multi-day transit pass all you have to do is show the pass to the driver when you get on, easy as cake.
Since you are a Rick Steves fan, you know that some of his organized bus tours come with free earplugs. I mention that because the chain hotel (over $100) we once booked in Mitte (Berlin) turned out to be on the curve of a tram and had no air conditioning. In July, it was impossible to sleep through the frequent screeching turns of the tram, with the windows wide open. So check the map a second time!
You mentioned the Coellner Hof in Cologne and that "rates average 75-85 euro per night" I contacted the Coellner Hof (it looks great on the web site), but the rate for a Thursday night was €109. While I don't want to sound cheap, the €85 to €109 spread is about $30 (not including tax and parking cost). I could use this to by lunch. Do you have any other suggestions for Cologne? We will be driving so we could stay some distance from Center City so long as there is an S-Bahn or U-Bahn stop nearby.