I've got the DLink Rangebooster N :
http://www.memoryexpress.com/Product...14361(ME).aspx
Not bad for the price. You could certainly do better then it for 20-30$ more though.
For a cheaper "G" solution:
http://www.memoryexpress.com/Product...15380(ME).aspx
There are Linksys equivalents but they tend to run a bit more in price. I'd wager that Dlink an Linksys offer similar quality products for the home market, but I've never had direct experience with Linksys products.