I have become a huge fan of both sightron and vortex recently. There are a lot of manufacturers putting out a great product with lifetime warranty
attached. From what I have heard from those who know more than I, the old Leupold Vari-x series were much better than the current VX series.
You can pick up a used vari-x II 3-9x40 on EBAY for around 150 - 200 and you still get the lifetime, no questions warranty. If not that, look at Vortex!