ZyXEL's are indeed very well respected here, see my post signature.
As j0hn has said, the VMG1312-B10A usually performs very well on most lines but is getting quite hard to obtain now at realistic prices.
I recently added a VMG3925-B10B in router only (bridge) mode to my system, bought this "new" on e-bay for £30 + P&P, there are still a lot of older model XyXEL's available on e-bay at very good prices, just ensure they are not ISP "locked down" units unless you have the capability/wish to take the trouble to unlock.
Cross posting acknowledged: