Forbes covers the top 9 corporate hate sites:
Sometimes it seems that shoddy products and atrocious customer service go together like peanut butter and chocolate.
But while your average disgruntled consumer simply vents their bile by bellowing at a bewildered service rep, a few go farther. Much farther. These perennially peeved people build–and obsessively maintain–sites devoted exclusively to complaining about their least favorite corporations.
To honor these quixotic champions, we spent hours trawling the Web looking for the very best corporate hate sites. After checking out more than 100 sites with names like dontflycontinentalairlines.com and fordlemon.com, we rated the best of them on a scale from one to five in six different categories: ease of use, frequency of updates, number of posts, hostility level (angrier is better), relevance, and entertainment value (Hey! Angry and funny!).
The article is interesting, but in case you just want the cheat sheet, here you go:
PayPal (part of eBay)
UAL (parent of United Airlines)
United Parcel Service