Well, any of the DG834 range to be honest, depending on which features you need...
DG834 - ADSL/Router/Switch/Firewall DG834G - ADSL/Router/Switch/Firewall + 54Mbps Wireless DG834GT - ADSL/Router/Switch/Firewall + 108Mbps Wireless
Then they get a bit silly about wireless bandwidth...
Fair fucks, but not really much use unless you've got multiple machines in your gaff playing games against each other. The speed of the web access is just the same.
This one DG834PN is pretty much the daddy at the minute.
Again the only difference to the 834GT is (supposedly) 10 x wireless speed. Which is great, but won't matter unless you've got more than one device talking to each other wirelessly. They also claim 10 x the wireless range, but not sure how valid this claim is.
For most purposes, and depending on how much cheaper it is, the GT is probably all you'll need
For comparison... I saw one of the PN ones go brand new off t'bay recently for 40 quid, which is pretty damn cheap.