
I've always preferred Karcher - IMO they're the best on the domestic market for the price point. You should be able to find some good deals on line for various models.
The downside of trying to compare like for like in larger retail/DIY outlets is that they tend to give different model numbers exclusive to each chain so I'd recommend you compare the individual features for each on-line and not just prices. You may find you get extras such as lances etc that make one a better buy than another too.
regards, Teri