The Garmin GPSmap 60CSX is my personal favorite. It is rugged, survives drops/crashes, very water resistant, tough display, acquires signal fast, good reception under canopy, long battery life (2x rechargeable AA), accepts optional external antenna, has MicroSD card (max 2GB), all of the features (data/displays) you would expect for cycling & navigation, mounts well on handlebar, USB connection for import/export, customizable settings/displays, lots of misc/fun stuff, etc.
If you want cadence or heart rate and have the additional sensors - look at the Garmin Edge 705 ($400). However, I don't think it is as durable.
You would also be fine with the earlier model, the Garmin GPSmap 60CS. They are virtually the same.
- CSX has color screen
- CSX has removable microSD (CS only stores 10,000 points in active log and simplifies saved logs)
- CSX has upgraded GPS sensor (faster acquire, better under canopy/urban valleys)
However these differences do not really impact the average user. If you don't need detailed logs with more than 10,000 points or want to load color imagery, which is not easy anyway, you would be very happy with the CS.
I have been using both models since they were released, and none have failed or ended up in the unused gadget drawer. I use them instead of a cycling computer/speedometer.
You can find both models online. The CSX is about $250. You might be able to find a CS for $150.
Tip: Use the provided lanyard when bar mounted. Wrap the lanyard around the handlebar and pull the GPS unit through the loop as a sort of safety line. This is a necessary backup in case of big bumps that can cause the unit to pop out of its bar mount. If not secured with the lanyard, the unit can pop out and fly across the road into traffic. With the lanyard, it will merely dangle from the bars and avoid potential damage. It's only done this 3 or 4 times over the last few years. The first two times the unit wasn't secured and landed hard on the pavement at speed - but no damage!