Love:

-observing the ducks and birds in the marsh area on the first :15 minutes of my commute.
-"magic hour" lighting at the end of the day on my ride home. Sometimes I stop to take a photo.
-my work hours vary, but I'm starting to recognize some of the people I encounter on my commute and say hello or wave.
-passing cars when car traffic is bad
-tailwinds
-saving money on gas and not contributing to car exhaust in the air
-getting exercise while traveling rather than sitting and getting a stiff back
-more opportunity for interesting experiences & observations. I used to bike commute into San Francisco daily. As the sun was setting, while riding on the golden gate bridge, I passed a guy biking with goggles and a cape and he had a backpack with a small dog in it - and the dog also was wearing goggles and a cape. More recently, I took a trail shortcut through the marsh on my way home and encountered cops heading out to remove homeless people that were sleeping in the marsh. I definitely have more "interesting moments" when I cycle to and from work.

Dislike:

-any significant wind that is not a tailwind
-debris and broken glass in the bike lane, especially on my way to work when this makes me anxious about getting a flat and then being late for a meeting.
-stoplights that don't detect my bike. I recently contacted a city traffic department staffer about one particular light and he said this: "you just don't have enough ferrous metal on your bike to set off the light." Cyclists in my area get $500 fines for running stoplights and stop signs.
-Running late and having to get dressed really quickly when I get to work and then scrambling to my first meeting while still a bit sweaty and then realizing my sweater is inside-out in the middle of the meeting...
-professional dog walkers on the bike path walking five dogs at a time, all on retractable leashes...
-trying to pass pedestrians with loud headphones on