Back in August I started using Verizon's VoiceWing VoIP service for my home business line.
So far the quality has been spotty, and the service is utterly useless when I'm using interactive applications such as Microsoft's FolderShare (likely due to the fact that my cable modem's upstream bandwidth is less than 400k on a good day).
However this weekend I purchased a D-Link DIR-635 RangeBoost home wireless router. The RangeBoost has an internal QoS engine (I'm assuming it's nothing more than simple weighted-fair queuing, but they don't provide any details). After installing it and calling a few people I'm noticing a huge improvement in VoIP call quality, even with FolderShare running. I even made a call using Skype across my home wireless network (with a Bluetooth headset), and the call quality was very good. What really sold me on the D-Link device was the cost, I paid $130, before a $20 mail-in rebate. The last time I searched for QoS-enabled home routers, the cost was about $250 on average.
Unfortunately the DIR-635 is a pre-802.11n device, since the standards haven't been finalized, so if you want to take advantage of n's speeds, you need to buy D-Link adapters for all devices. However I think it's a safe bet that once 802.11n is ratified, all it will take for compliance is a firmware update, but that's not a guarantee.
But, 802.11n isn't required for QoS, so even with plain old 802.11b/g adapters, you'll get the benefits of prioritization of outbound traffic, and greater quality for QoS.