I've used both Lexar and Sandisk with pretty much equal success. I had some Sandisk cards fail on me about 10 years ago, but since then, the only other card I've had fail was a Delkin.
I think Lexar and Sandisk haver similarly good products, they both have some who have had problems, but the problem rate is rather low I would think. Those who do have problems are very vocal, of course, and may make it seem that the products are worthless, and that is understandable. If you've had a number of Lexar cards fail on you, then you are not likely to continue to use Lexar and I wouldn't blame you. But you can find this is the case for any card, I'm sure.
If you really want the highest quality card, and are willing to pay for it, you can get the Transend 300x UDMA 16GB, which have a different type of error correction built in:
http://www.amazon.com/Transcend-300x-CompactFlash-Memory-TS16GCF300/dp/B0017NO1H2Be careful, though, not all Transcend cards use this technology, and I don't think the ones that don't have as good a reputation as either Lexar or Sandisk, from what I can tell. The only Transcends I know for sure have this is the one I linked to, and you can tell by the price (almost 3x the price of the regular Transcend cards), it's not cheap technology.