A few days ago I posted a call for help regarding my upcoming purchase decision of a digital SLR.
Wow. Canon versus Nikon feels like Apple versus Microsoft!
Most people in the comments (by the way, thank you, thank you, thank you) favour the Canon, but in the grand scheme of things I think it comes down to personal preference and your history with either vendor. If you've got a lot of time and history (especially lenses) invested in a particular vendor, then you're much more likely to stick with them.
After reading the comments and cruising websites, it feels very much like a religious war, similar to the Microsoft versus anyone else debate.
Anyhow, make of that what you will, but I think I'm going to be non-conformist and go with the Nikon D200. I went to the local camera store that I've done a lot of business with (I even bought one of the first digital cameras there back in 1996 - a Casio something-or-other that had a 320x240 resolution - no mega pixel there and no flash - it was useless) and had a long discussion with a Canon owning sales guy who was incredibly passionate about the topic.
He laid out all the facts and led me to the conclusion that the Nikon is better for me.
Respect. Cameras West in Bellevue. Highly recommended.