I've been using
DriverMax for some time and have been extremely satisfied.
They offer both a free and paid version.
The free version allows 2 free driver update downloads per day and the Pro or paid version ($39.95 for 2 years) allows unlimited
instant downloads of new drivers.
For me this has come in handy when updating a machine to Windows 7 and making sure there are compatible drivers available especially
in the case of some outdated drivers when changing over an XP system.