Shelby--a long weekend is London, you lucky girl!
We went in 2000 & stayed here...
http://www.premiertravelinn.com/pti/home.do
"Travel Inn London County Hall
Enjoying a prime location that's just a stone's throw away from the London Eye, the Travel Inn County Hall is also handy for the Southbank and Westminster.
With a Potters restaurant and bar also on site, the hotel represents unbeatable value for a family of four visiting London. Other decent restaurants can also be found nearby, while the Eurostar terminal at Waterloo is less than 5 mins walk away.
Room services: colour TV, coffee/tea making facilities, en-suite bathroom (with bath and shower), radio alarm. On request: free cot, hair dryer, iron + non-smoking rooms Hotel services: bar, currency exchange, restaurant"
The rooms were comparable to Best Western or Days Inn. They were VERY reasonable & friendly. We were only a 5 minute walk from Waterloo Station. When they say "a stone's throw" from the London Eye that is NO EXAGERATION. It was right at the backside of the motel. Big Ben is also right around the corner of the building & across the river...a 5 minute walk.
There is also another more prestigious Hotel in the same building but I can't remember the name. Do a search for County Hall London & I'm sure it will come up.
Whichever hotel you decide, I highly recommend the location.