How advanced does it need to be in terms of what you can configure as a user, i.e. do you want something totally flexible or with just some basic QoS presets?
If you don't mind spending a bit more then DrayTek would be your best bet, they will offer QoS features that you simply won't find on any other "home" routers and are also very reliable.
You could also consider running some custom firmware on a Linksys WRT54GL and using an external ADSL modem, check out the tomato and DDWRT offerings to see if they would meet your needs.