I just bought a new washing machine last week too. I went to homedepot.com, BIgGeorges.com and lowes.com and compared prices on the revised version of my old machine: a Whirlpool Duet. I got a good deal, 30% off from Home Depot. Decide what type you want --front loader or top loader--, what brand, then start checking prices for the 4.5 cu ft and 4.3 cu ft and see who has the best offer. Lots of these machines are stackable. The appliances section of the websites for both these companies show you which are stackable. Then, read reviews and see what you think ...
Clare