WRT54GX
The WRT54GX, released in the beginning of 2005, uses hardware to increase its speed and range.
Linksys: Official Firmware, least features, most stable (Latest Version: 1.02.10)

WRT54GXv2
Linksys: Official Firmware, least features, most stable (Latest Version: 2.00.08)

WRT54GX200
Linksys: Official Firmware, least features, most stable (Latest Version: 1.01.14)

WRT54GX400
Linksys: Official Firmware, least features, most stable (Latest Version: 1.00.17)