I bought a Diamond WR300N within the last couple months because I wanted to get wi-fi in a part of my house where it simply wasn't - our regular router is on the 2nd floor near the front of the house, one of our internet-capable TVs is on the 1st floor "around a corner" from the router room and shielded from it by our "1st-floor" garage's walls that have aluminum-foil backed insulation within them. The repeater was placed in another 2nd-floor room above said TV and we have full-strength there now.
Perfect solution.
Note, however, that repeaters halve the data speed since they have to send and receive twice between router and device.
http://www.runaroundtech.com/2011/08/26/review-diamond-multimedia-wr300n-wireless-range-extender/