RE: NEW SIGHT
I'm using a Spot Hogg now and have been for the last 4 years. I can't see myself changing sights anytime soon. They really hard tough as nails and very accurate.
That being said, it really depends on your price range. The Axcel sight mentioned above are a very good sight, but you'll pay for them. Most of the high end hunter class sights are going to run you 150.00 or more.
Another nice sight not mentioned are the new Octane sights. They look a lot like the Spot Hoggs in many ways and should prove to be just as rugged and dependable.
If you can't spend that kind of cash on a sight, take a look at the Copper John sights. They're very reasonably priced and very well built.