I use wired on one of my bikes (ciclosport, don't remember the model number but it's the most basic unit). I actually like it better than one of my wireless units because of reliability (one battery and it just works). All I really need is a clock, total distance, current speed. I really don't even care about average or max speed and other stuff.

One of my wireless computers (Trek model with cadence and HR) has an integrated HR monitor and a host of other novelty functions like temperature, altimeter, gradient, etc., and that's pretty cool and all except there are three batteries you have to keep switching out (one for the computer itself, one for the wireless unit, and one for the HR strap).

The best wireless computer I have used is the Cateye Micro Wireless. It's around $35 online so it's not terribly expensive, it's a small unit but very easy to read, and it just works (signal doesn't drop, etc.).

Stay away from Sigma.

http://www.bikeradar.com/gallery/art...news%2Farticle
Picture 18 shows Tom Boonen's bike. He actually uses a wired computer.