Before we start I'd like to appologise for using Apple.com for the prices, but Im in the UK...
Sennheiser CX300 Ear-Canal Headphones $60. I had a pair for a long time and they sound pretty good.
You can Bose in ear phones for $100. I’ve never tried them but I know a number of people who say they good.
I have a pair Shure SE110’s ($90) mainly because they were the first I saw that you could use with an iphone (you can get a little adapter thingy with a mic and a button). The sound could be better but they are really comfortable. The foam tips they come with are damn fine.
For everyday use I go with ultimate ears super.fi 5pro which I love but they may be out of your price range.