Get the cheapest 802.11g (“Wireless G”) of the major manufacturers (Linksys, Netgear, D-Link, or other major brand that you know and trust).
WiFi technology, though packaged for and widely used by consumers, is inherently complex under the hood and subject to a broad range of issues that can’t be reasonably discerned/diagnosed by a non-expert. So it is common for us to experience these devices as being unreliable. That being said, I’ve researched and used a wide range of products, and have found the goodness and badness to be spread all about. So I have found it best to treat it as a commodity and go with the lowest price. This strategy has worked well for me. (Note: I would be qualified as an “experienced network engineer”.)
Finally, avoid the Super Duper features that purport to provide greater speed/distance or that use the newest “bleeding” edge standards. These added features, in addition to adding cost, add complexity and have a strong tendency to reduce product reliability.