Cozy hotel, ideal location
Somewhat accidentally found this hotel after searching my "regular" hotel on Union Square bumped their prices from my previous stay there. A quick search on tripadvisor yielded this superb, economical find.
The rooms are small, reflective of an "older hotel," but well-appointed. The staff is extremely friendly and willing to assist as best they can--they even offer day/multi-day passes for the cable car/streetcar/bus lines which offers a tremendous value to travelers. 
Be aware, though, if you're looking for a late night bite, or a cocktail, the bar and smallish restaurant close early (around 9:30). But there are plenty of other walkable nearby options if the mood strikes you there. The "business center" such as it is, consists of a computer on a desk next to the reception desk. But it served my basic functional needs.
So, in sum, The Chancellor is not luxurious (and is the reason I did not give it all five stars), but it is very comfortable, and almost quaint. And for my visit (early February 2012) very reasonably priced as well.