I Like the Cateye Strada bicycle computers. I have a wired Strada and a double wireless (wireless speed and cadence) and my wife has a wireless Strada (no cadence). All are good quality units. The double wireless sensor is a bit of trouble to set up, but the single wireless is not trouble.
Another brand worth looking at is the Sigma Sport computers. They are somewhat cheaper, but still reliable. If you choose a Sigma Sport computer, I suggest you also buy the power magnet. The magnet that comes with the Sigma Sport computers works, but the power magnet makes the unit more reliable.