Miller, Miller, Miller. Or, as an alternative, Hobart. They're essentially the same helmet now. And...Northern or TSC should carry them. There's a $100 model, a $180 model, and one above that. I would highly recommend the $180 model, as it is an updated version of the Miller I currently use and love for several hours a day. The $180 has a faster reaction time, more adjustments, and an Auto-On feature; meaning if you forget to turn on your helmet, it does it for you when you strike an arc! I wish mine did that. This is one place I would never recommend anybody skimp and get the HF or Northern POS. They are absolute garbage. They blur the welding area, sit too close to the face, the headgear is junk, and they weight a ton. I have a friend who was using a HF for years. I kept trying to get him to get a Miller. I told him the helmet would make him a better welder. He finally picked up the $100 Hobart, and fully agrees with me. His welds DID end up looking significantly better after the purchase.
Basically what I'm saying is this: These are your eyes, the only set you have. Why blow money on crappy protection when for a little more you can have real protection? The $100 Hobart is enough to get by, and definately better than the Northern, but I'd say spend the extra $80 and get the step up. You will NEVER regret it!
Go here and check out the helmets. Don't look at the Pro-Hobby FS-10, it's a fixed-shade, and you don't want that. 10 isn't dark enough for a lot of MIG welding. Run it as dark as you can stand it. But anything above the FS-10, starting at $16, is going to be a good helmet. I use the older version of the Performance series. Compare specs and choose wisely. Northern or TSC should have the Hobart equivalent for about the same price as those listed for the Millers.
Can you tell this is a subject I'm passionate about?
