I recently upgraded from this excellent 85mm/1.8 to the legendary 85mm/1.2L II ($1700), which is in a completely different league. See its gallery parallel to this one.

This was my favorite lens when I had a 1.6x crop body (20D). At $350, this is a must-have for any Canon 1.6x-body user who can't afford the 85mm f/1.2L II or needs faster focusing. This lens auto-focuses very reliably and quickly on a 1.6x crop body and is also great for indoor sports such as basketball.

With the full-frame 5D, the 135mm f/2L has about the same field of view as an 85mm on the 20D and more sharpness and color saturation than the 85/1.8, so I used the 135mm more with the 5D before I got the 85mm f/1.2L II, particularly outdoors where there's enough room to back up for portraits. The 85/1.8 also loses some color saturation and contrast as it's opened up below f/2.8. That said, the 85/1.8 takes some very sharp and contrasty photos stopped down a little.

An alternative in the same price range is Canon's 100mm f/2.8 Macro. It allows you to get in much closer (5.9 inches) and is just as sharp. You obviously need more light or higher ISO, though. And you won't be able to blur the background as much.

I recommend the The-Digital-Picture.com for comprehensive reviews.