I've wanted to see a Brown Recluse for years, but never get lucky.
It has a brown fiddle on it's back. But don't be afraid, it's a "reclusive" spider, preferring to keep away from people.
Most of the spiders I've seen are harmless. The biggest one I saw was a beautifully colored spider with a leg span of about two inches. It appeared one morning in the garden, sitting in the middle of it's web, waiting on breakfast. Once I actually walked through one of it's webs, and did I panic! But it scurried off to build another web, since I was too big a sandwich for him to get his mouth around!
I like the hairy ones that stalk their prey like a tiger. I don't think they build webs and they're kind of small, but boy are they cool.