I was looking at the Polar site for a heart rate monitor and there are many choices. Figure I'll ask for some recommendations here. What do you guys use and why do you like or dislike it?

I use the ANT+ that came with my original PowerTap. It pairs up neatly with my Garmin 500.

I had a Polar. It worked fine, but only pairs up with Polar heart rate monitors and they are behind the curve in adopting ANT+. If you do get a Polar, you'll find that a 2 Euro coin is the right tool to use to open the battery cover when it needs replacing.

I use anything NOT polar anymore. The chest transmitters don't last long, yet cost almost as much by themselves as the entire monitor from many other brands.

Check out Suunto. They're a Finnish company and I've been using one of their HRMs for ~8 years and it's still going strong. I have one of their dive computer too.

https://www.suunto.com/

For the past year or so I've been using a Garmin 705 on the bike, but still use the Suunto for spinning, working out, etc..

Garmin Edge 500.

The ANT+ heart rate transmitter with packetized digital transmissions doesn't get ludicrous readings near power lines/traffic lights/??? like my old 5KHz coded Polar CS200 CAD, it downloads to my computer via USB cable so I can track training load/stress balance via heart-rate based TRIMPS when my power meter is in for repair (having done that I wouldn't waste money on a computer without the download capability), the back light can be configured to stay on for night rides, the screen can display up to eight fields with whatever I want, unlike the Polar it's hard to reset accidentally (an accidental second push of the stop button ended a ride), the Garmin GSC-10 speed/cadence sensor locates on top of the left chain stay where it can't get bumped unlike the down tube mounted Polar cadence sensor, the sensor was easier to set up since it has leds which flash with each revolution following reset, and the sensors have user replaceable batteries.

The Polar conductive fabric chest strap was nice, but you can mate it to a Garmin transmitter so that advantage is not unique to the Polar.

Figure out how you're going to use it, and what features you need. When I was training by HR, all I needed to track was current HR, average HR, and Max Hr. For that, you can use the cheapest HRM from any of the major manufacturers.

I wouldn't pay a lot for a fancy HRM with lots of features, unless you've got a specific use for those features.

I'm sure I dont.....

The Garmin Forerunner 305 for the money cannot be beat. It can be used for running and cycling gives tons of info, easy to read and use, and is completely reliable and inexpensive.

+1 I'm on a very basic HRM now. I do miss the dual timer feature for intervals, and a zone alarm was useful for time trials back in the days when heart rate was the determining factor.

I use a Suunto T4D. I also bought a compatible Bike Pod which is essentially a front skewer (from Mavic) with a wireless speed pick-up that the T4 recoginizes. That way I have one device for both HR and speed/distance. Works great.

Stay away from Polar. For the most part they are not user maintainable and you have to ship them back for things as simple as battery replacement. My workout bag has three dead ones I still carry around.

My polar was always being returned for warranty repairs. I went through 4 heartrate monitor straps in two years. I now use garmin.

apparently, YMMV...

i have a polar RS100 (pretty satisfied with it...basic but effective) that i got probably...4 years ago? still have the chest transmitter it came with and it still works fine. and i use it a lot.

I use the Garmin Forerunner 405 and like it real well. Use it for running, on the bike, and in a tri will swim with the strap and put the watch on as I ride the bike.

I bought the premium garmin chest strap to use with my oregon gps and it worked great but the oregon just didn't make for a good cycling computer so I finally got an edge 500 and use the same strap. It works great. In several dozen rides so far with the strap I had one incident of an odd reading when my hr apparently jumped up to 202 for a second and based on the graph is clearly a mistake. That, however, is the only issue I've had so far. The strap that comes with the bundle is not, I think, the premium one but a basic one that people seem to have more issues with.

I must have gotten a few duds. The Polar Vantage XL I got in 1994 had a chest strap that lasted until 2006. Either way, the HRM I got was $35 and allows the user to replace the batteries in both the watch and the chest strap (about $3 each from a local drug store).

nah, you're not the first person i've heard comment on the short chest strap life - i think i just got lucky. user-replaceable batteries definitely seems like a better idea.

My Bontrager Node computer with the HR monitor works great.