Ciclosport C414M is the one I like. I have use a dozen or so over the years. Al have been just fine for the basics (speed, ave, time, dist, trip). The C414M does altitude and gradients too which I like. Plus it is downloadable into the computer and graphs the rides.

Here is a screenshot of the graphing. You can flag parts of your ride for reference when riding (or afterwards).

http://ricemobile.net/cgi-bin/i/junk/cm414.jpg

I love it. Plus it has cadence option to ($15 extra) that I use and that puts the wheel sensor on the rear wheel. Then you have the orignal wireless setup for another bike (it has a two bike memory).