I strongly suggest getting a high powered router. Buffalo and Netgear tend to be favorites, though the new Asus routers are really nice and are well liked.
I use the Buffalo WHR-HP-G300N with a high gain antenna (19 dbi TP-Link) and have 0 range issues. The whole setup was about $90.
While anecdotally you might hear the G is better, N will maintain the same throughput with a poorer signal and will have higher throughput on a higher signal. G and N operate in the same freqencies but N uses more channels within the frequency. 5GHz N is actually fairly rare on PCs, most consumer gear only supports 2.4GHz as 5GHz is an optional part of the spec.Small Net Builder
has good advice and reviews.