Pension ABC puts you within a 10-minute drive of Brandenburg Gate and Checkpoint Charlie Museum. Free perks include buffet breakfast daily and WiFi. Also, Reichstag Building and Potsdamer Platz are within a short drive.
Pros: Great location. Nice staff. Clean. Nice sized room. Large windows. Close to U-bahn stations. Value for price. Cons: Mattress was a bit lumpy at first (not a spring mattress). Note there's a 10 Euro surcharge for checking-in late in the evening. There is an elevator, but you need to climb a few steps as well, in case that's an issue.