First, consider using the cable/DSL model that your DSL provider supports. That makes life simple for evermore. I do not know of a tech support team for any DSL or Cable internet provider who will even talk to you if you use a DSL unit they do not support. Nor will they provide tech support, in most cases, or warranty any of the work or connections.
Beyond that, Cisco is the best, but expensive. Allied makes a terrific one. Motorola is good, along with LinkSys, Netgear, many DLink, 2Wire, Toshiba, Buffalo, and a number of others.
We recommend avoiding the SpeedStream, Best, Network Everywhere, ZyXel, EnGenius, and Belkin (because the Belkin is not made by Belkin, but by a number of other manufacturers for Belkin) and varies from month to month and market to market.
If you need model numbers, we have most of them available.
When we are given the choice, we use either Netgear RangeMax, or the new LinkSys dual antenna models.
Most Wireless modems for DSL or Cable are good and reliable nowadays. If not, they could not stay in business as the cable and DSL companies ban all the rotton ones.