Skip harbor freight. Hobart makes a real nice auto darkening adjustable hood that generally runs between $100 and $150. Spend the money, its your eye sight and its worth it.
The lense can be adjusted for shade, which is a nice feature, and I think its also adjustable for sensitivity and delay which helps alot if you're going to be welding outdoors or in different set ups that affect the lighting around you.
The hood/mask is lightweight and offers good coverage. Its not rated for overhead or out of position welding, but thats not a huge deal for most folks.
Personally, I use a hunstman adjustable lense in a jackson hood/mask. Its a good set up, but costs quite a bit if you're not going to be using it alot or welding in odd postions where you need the heavier hood.
Jackson makes a nice hood with an adjustable lense also, and I think they may have some cheaper hoods that are fixed shade, but electronic lenses so you don't have to flip them up and down. You might consider one of these if you only stick or mig weld. A #10 lense is good for general use.
I'd really pass on any of the cheapo import stuff in this case. And be sure that whatever you buy uses stanard sized parts so you can buy new cover plates for the lense. Using one thats scratched up all the time sucks.
EDIT
I'd recommend one like this
http://www.migweld.com/Black-XTV-Welding-Hood-p/770424.htm
Look at how much faster the reaction time is for that lense compared to the cheaper ones. And you have the other adjustments to fine tune it as well.
I really like having an adjustable shade lense. I generally run it around a #11 for mig or stick welding. If I'm welding outside and have a lot of sun coming in the back of my hood the glare can get annoying. So I'll switch to tinted safety glasses to take care of the glare and then bump the lense back to around #10.