I just recently bought a laptop from Grnamin and it came with a linksys Wireless-G adapter. For it, I bought the exact same router you are talking about, the Linksys WRT54GS, and it works just fine. I have DSL service in every room of our house. The DSL modem, router, and desktop pc are all in the garage. The house is 2300 square feet. So, I don't think the problem is that the router "sucks" or anything.
Here's the funny thing.... Maybe I just don't know how to follow directions, but I'd swear that the installation CD gave me incorrect instructions! I hooked it up in the manner that I was instructed (or so I thought), but eventually switched the wiring to the way that made sense to me. I thought the instructions said to hook up the DSL cable (coming from the phone line) to the router. Anyway, that didn't make sense to me, so I hooked it up like this: The cable from the phone line -->to the DSL modem, the Ethernet cable from the DSL modem -->to the router, the Ethernet cable from the router -->to the computer.
Seems so logical that I think it's a little strange that I understood the CD's instructions to be different!
I still didn't have service, but it was on the part of the adapter. I had trouble installing the drivers for it onto the laptop (the drivers weren't included with the adapter). I downloaded them from the Linksys website, but couldn't get them to fully install. The way I found that out was through the Linksys's website, which you may want to try. There is a function on there website that will scan your computer and hardware to see what the problem is. You get to it from "Support"-->"Technical Support"-->"Easy Connect"-->"Router's initial setup.....". Although, even though the Linksys website told me that the problem was that the driver were not fully installed, it could not do it for me, and didn't solve the problem.
The way I finally solved the problem was to go to the Microsoft updates website. I selected the "Custom" update check option. Then it found some updates that I wasn't interested in....But there is this option on the page after it finds the updates, "Hardware"...I clicked that and it found that my wireless adapter wasn't function properly and suggested I download the "update"....I did it, and everything's been working fine ever since.
Hope this info helps. I'm definitely satisfied with the Linksys WRT54GS, I've had *zero* problems with it so far.
Fast link the Linksys help you need:
Linksys Help
Microsoft Update Site:
Microsoft Updates website