When most people go to look for a networking device (adapter, switch, access point, etc.), with so many options, they go with a brand they trust, Linksys and Netgear usually ranking at the top. What most people don't know is the difference.
I've been on IRC channels where people ask what's the best switch to get. The little secret I usually tell them is they're all the same. Netgear, DLink, Linksys, even the cheap "Airlink" wired switches we have at work all run on a switch provided by a vendor, usually Marvell or Broadcom. Given that chip, making a switch is little more than a EE senior design project.
But what about more complicated things like routers? Same thing. Look at the OpenWRT table of hardware (OpenWRT is an alternate OS that you can use on a router). Despite all the brands, the chips are almost all made by AMD, TI, Atheros, Mavell, and Broadcom. Routers can be a bit more complicated, but the extra components (CPU, switch, wireless) are still made by the same handful of vendors. The only real differences are in software and how well the parts were put together.
So all Netgear and friends do for routers is buy the same parts their competitors did and connect them. What about network adapters? Same story. It turns out the pretty cover on your Netgear WG311 covers a mini-pci card (this is what goes into laptops, and even some routers) with an Atheros chip. So Netgear does almost no manufacturing on products and just plugs them together, but what about the Cisco Aironet line? This is Cisco, a company aimed at businesses demanding stability. You guessed it, the same Atheros chip as Netgear.
It even goes beyond networking. When Sony laptop batteries started to explode, people quickly learned that Sony laptops weren't the only ones affected; IBM/Lenovo, Dell, and others all bought batteries from their competitors.
Next time you go look for a new TV, LCD TVs will probably be a serious contender for your business. So what brand should you get? Is one better than another? Yes, but not the brands, themselves. There are only a handful of vendors that produce LCDs. Every company that makes TVs or monitors buys from these vendors. Now, the vendors produce different quality products, so that Sony LCD TV will probably look better than the Best Buy store brand Westinghouse, but word is Sony gets their LCDs from Samsung. It isn't quite this straightforward. Many TVs do post processing, so that the compression artifacts you see on a low end TV are blurred by higher end TVs (despite what most people think, neither DVDs nor HD content is perfect. It's compressed, so at certain times, if you know what to look for, you can see compression artifacts. Analog signals are compressed, too, but their artifacts are always present).
Basically, once electronics became commodities and prices fell, a few vendors started making all the parts that go into virtually everything, and most brands just put these parts together.
I was looking for a SATA controller for a friend a while ago. Instead of going for the name brand, I got the generic card with a chipset I recognized. The card was simply a PCB with PCI connections, the chip, a few discrete components, and SATA connectors--nothing special. The card worked, and despite not being a name brand, it even worked in OSes like Linux and FreeBSD. Because it was generic, the chipset had to be widely supported, so almost every OS supports it, without some of the headaches of first party chipsets, a la Promise.
The lesson: all that matters how is how well the package was put together. Is the software user friendly? Did the EEs remember to put a big enough heatsink on the CPU? Is it pretty like an Apple product? These are the things that matter, now. For some things, like network cards, there isn't a UI. The thing to look for here is a common chipset. If lots of brands use it, the drivers will likely be more mature at work better.